UNIT 1 Number and Operations Additional Resources Personal Math Trainer my.hrw.com Online Assessment and Intervention Assessment Resources • Leveled Unit Tests: A, B, C, D • Performance Assessment Study Guide Review Vocabulary Development Integrating the ELPS Encourage English learners to refer to their notes and the illustrated, bilingual glossary as they review the unit content. c.4.E Read linguistically accommodated content area material with a decreasing need for linguistic accommodations as more English is learned. MODULE 1 Rational Numbers 7.2, 7.3.A, 7.3.B Key Concepts • A number that can be written as a terminating decimal or a repeating decimal is a rational number. (Lesson 1.1) • A subset is a set of numbers contained in a larger set. (Lesson 1.2) • To subtract a number, add its opposite. (Lesson 1.4) • The product of two numbers with different signs is negative. The product of two numbers with the same signs is positive. (Lesson 1.5) • The quotient of two numbers with different signs is negative. The quotient of two numbers with the same signs is positive. (Lesson 1.6) 49 Unit 1 UNIT 1 Study Guide MODULE ? 1 Review Rational Numbers EXAMPLE 3 1 - __ 2 . Find the product: 3(- __ 6 )( 5 ) Key Vocabulary ESSENTIAL QUESTION How can you use rational numbers to solve real-world problems? rational number (número racional) repeating decimal (decimal periódico) 3(- _16 ) = - _12 Find the product of the first two factors. One is positive and one is negative, so the product is negative. - _12(- _25 ) = _15 Multiply the result by the third factor. Both are negative, so the product is positive. 3(- _16 )(- _25 ) = _15 set (conjunto) EXAMPLE 1 Eddie walked 1_23 miles on a hiking trail. Write 1_23 as a decimal. Use the decimal to classify 1_23 by naming the set or sets to which it belongs. subset (subconjunto) terminating decimal (decimal cerrado) EXAMPLE 4 15.2 Find the quotient: ____ . −2 15.2 ____ = -7.6 -2 1.66 ⎯ The quotient is negative because the signs are different. 3⟌ 5.00 1_23 = _53 -3 20 -1 8 20 -18 2 2 Write 1__ as an improper 3 fraction. EXERCISES Write each mixed number as a whole number or decimal. Classify each number by naming the set or sets to which it belongs: rational numbers, integers, or whole numbers. (Lessons 1.1, 1.2) 4; whole number, integer, Divide the numerator by the denominator. 1. _34 _ The decimal equivalent of 1_23 is 1.66…, or 1.6. It is a repeating decimal, and therefore can be classified as a rational number. 0.75; rational number 11 3.66…, 3. __ 3 rational number 2. _82 rational number 4. _52 2.5, rational number Find each sum or difference. (Lessons 1.3, 1.4) EXAMPLE 2 Find each sum or difference. 4.5 5. -5 + 9.5 A. -2 + 4.5 5 8. -3 - (-8) -_23 6. _16 + (- _56 ) 9. 5.6 - (-3.1) -9 7. -0.5 + (-8.5) 8.7 10. 3_12 - 2_14 1_14 0 13. -8 × 8 -64 © Houghton Mifflin Harcourt Publishing Company 0 1 2 3 4 5 45 11. -9 × (-5) -56 14. ____ 8 Start at -2 and move 4.5 units to the right. -2 + 4.5 = 2.5 -7 17. - _25 (- _12 )(- _56 ) B. - _25 - (- _45 ) 12. 0 × (-7) -130 15. _____ -5 -_16 26 18. 34.5 16. ____ 1.5 (_15 )(- _57 )(_34 ) 23 3 -__ 28 19. Lei withdrew $50 from her bank account every day for a week. What was the change in her account in that week? -1 0 © Houghton Mifflin Harcourt Publishing Company Find each product or quotient. (Lessons 1.5, 1.6) -5 -4 -3 -2 -1 -50 × 7 = -350; -$350 1 20. In 5 minutes, a seal descended 24 feet. What was the average rate of change in the seal’s elevation per minute? Start at - _25 . Move | - _45 | = _45 unit to the right because you are subtracting a negative number. - _25 - (- _45 ) = _25 24 = -4.8; -4.8 feet per minute - __ 5 Unit 1 49 50 Unit 1 Number and Operations 50 UNIT 2 Ratios and Proportional Relationships Additional Resources Personal Math Trainer my.hrw.com Online Assessment and Intervention Assessment Resources • Leveled Unit Tests: A, B, C, D • Performance Assessment Study Guide Review Vocabulary Development Integrating the ELPS Encourage English learners to refer to their notes and the illustrated, bilingual glossary as they review the unit content. c.4.F Use visual and contextual support … to read grade-appropriate content area text … and develop vocabulary … to comprehend increasingly challenging language. MODULE 2 Rates and Proportionality 7.4.A, 7.4.B, 7.4.C, 7.4.D Key Concepts • A rate is a comparison of two quantities with different units. A unit rate is a rate with a denominator of 1 unit. (Lesson 2.1) • Two quantities, x and y, have a proportional relationship in which the constant ratio is k if y you can describe the relationship using the equation _x = k. (Lesson 2.2) • A graph represents a proportional relationship if it is a line that goes through the origin. (Lesson 2.3) MODULE 3 Proportions and Percent 7.4.D, 7.4.E Key Concepts • A conversion factor, or a ratio of two equivalent measurements, can be used to convert measurements from one system of measurement to another. (Lesson 3.1) • To find a percent of change, subtract the greater value from the lesser value and divide the answer by the original value. (Lesson 3.2) • A percent increase is also known as a markup, and a percent decrease is also known as a markdown. (Lesson 3.3) 141 Unit 2 UNIT 2 Ratios and Proportional Relationships Additional Resources Personal Math Trainer my.hrw.com Online Assessment and Intervention Assessment Resources • Leveled Unit Tests: A, B, C, D • Performance Assessment 143 Unit 2 Study Guide Review MODULE 4 Proportionality in Geometry 7.5.A, 7.5.B, 7.5.C Key Concepts • Similar polygons are identified by verifying that all corresponding angles are congruent and all corresponding side lengths are proportional. (Lesson 4.1) • Indirect measurement is a method of using proportions to find an unknown length or distance in similar figures. (Lesson 4.2) • In a scale drawing, the dimensions of an object are related to the dimensions of the actual object by a ratio called the scale factor. (Lesson 4.3) Review MODULE ? 2 Rates and Proportionality Key Vocabulary complex fraction (fracción compleja) constant of proportionality (constante de proporcionalidad) proportion (proporción) proportional relationship (relación proporcional) ESSENTIAL QUESTION How can you use rates and proportionality to solve real-world problems? EXAMPLE 1 A store sells onions by the pound. Is the relationship between the cost of an amount of onions and the number of pounds proportional? If so, write an equation for the relationship, and represent the relationship on a graph. Number of pounds Cost ($) 2 5 6 3.00 7.50 9.00 ? rate of change (tasa de cambio) Pay ($) 40 80 3 1 5 80 40 6 O 100 120 (6, 120) (4, 80) (5, 100) (2, 40) 2 4 6 8 10 Hours worked Key Vocabulary Proportions and Percent How can you use proportions and percent to solve real-world problems? conversion factor (factor de conversión) percent decrease (porcentaje de disminución) percent increase (porcentaje de aumento) principal (capital) simple interest (interés simple) Convert each measurement to meters. Use 1 yard ≈ 0.914 meter. $7.50 $1.50 _______ = _______ 5 pounds 1 pound $9.00 $1.50 _______ = _______ 6 pounds 1 pound 1 yard 40 yards 1 yard Length: _________ = __________ 0.914 meter 36.56 meters The rates are constant, so the relationship is proportional. © Houghton Mifflin Harcourt Publishing Company 4 120 EXAMPLE 1 June’s garden is in the shape of a rectangle with a width of 20 yards and a length of 40 yards. She plans to fence it in, using fencing that costs $30 per meter. What will be the total cost of the fencing? Write the rates. Plot the ordered pairs (pounds, cost): (2, 3), (5, 7.5), and (6, 9). Connect the points with a line. The total cost of the fencing is $30(109.68) = $3,290.40. (6, 9) (5, 7.5) 8 6 4 O EXAMPLE 2 Donata had a 25-minute commute from home to work. Her company moved, and now her commute to work is 33 minutes long. Does this situation represent an increase or a decrease? Find the percent increase or decrease in her commute to work. (2, 3) 2 2 4 6 20 yards Width: _________ = __________ 0.914 meter 18.28 meters Find the perimeter P: P = 2 + 2w = 2(36.56) + 2(18.28) = 109.68 meters Cost of Onions 10 Cost ($) The equation for the relationship is y = 1.5x. 2 160 ESSENTIAL QUESTION unit rate (tasa unitaria) $3.00 $1.50 cost ______________ : _______ = _______ 1 pound number of pounds 2 pounds The constant rate of change is $1.50 per pound, so the constant of proportionality is 1.5. Let x represent the number of pounds and y represent the cost. MODULE Hours worked Juan's Pay 200 8 10 Pounds This situation represents an increase. Find the percent increase. EXERCISES amount of change = greater value – lesser value 1. Steve uses _89 gallon of paint to paint 4 identical birdhouses. How many gallons of paint does he use for each birdhouse? 33 – 25 = 8 (Lesson 2.1) 9 percent increase = ______________ original amount 2 _ gal amount of change 8 __ = 0.32 = 32% 25 2. Ron walks 0.5 mile on the track in 10 minutes. Stevie walks 0.25 mile on the track in 6 minutes. Find the unit rate for each walker in miles per hour. Who is the faster walker? Ron: 3 miles per hour, Stevie: 2.5 miles per hour. Ron is the faster walker. © Houghton Mifflin Harcourt Publishing Company Study Guide 3. (Lessons 2.2, 2.3) The table below shows the proportional relationship between Juan’s pay and the hours he works. Complete the table. Plot the data and connect the points with a line. (Lessons 2.2, 2.3) Pay ($) UNIT 2 Donata’s commute increased by 32%. (Lesson 2.1) Unit 2 141 142 Unit 2 Ratios and Proportional Relationships 142 EXERCISES Convert each measurement. (Lesson 3.1) B. Find the unknown angle measure y. 1. 7 centimeters ≈ 2.76 inches 2. 10 pounds ≈ 3. 24 kilometers ≈ 14.91 miles 4. 12 quarts ≈ y = 35° 4.54 11.35 EXAMPLE 2 Use the scale drawing to find the perimeter of Tim’s yard. liters 5. Michelle purchased 25 audio files in January. In February she purchased 40 audio files. Find the percent increase. 60% increase for the dog? (Lesson 3.2) 63 pounds MODULE © Houghton Mifflin Harcourt Publishing Company ? 4 Q 3.5s; $17.50 Proportionality in Geometry How can you use proportionality in geometry to solve real-world problems? Write a proportion using corresponding sides NO and QR, NP and QS. Write a proportion using corresponding sides NO and QR, NP and QS. Substitute the known lengths of the sides. x = 7 cm Key Vocabulary 6m circumference (circunferencia) corresponding angles (ángulos correspondientes) 59° 65° 4m 80° 90° 125° 8m T 15 m P 10 m N 80° 60° 6.5 m 9m O 85° 12 m R 125° S 1. Are the four-sided shapes similar? Explain. No; Corresponding angles do not have the same measures. corresponding sides (lados correspondientes) Also, corresponding sides are not proportional. For example, diameter (diámetro) indirect measurement (medición indirecta) angles N and R do not have the same measure, and PO ___ MN _ 4 ___ = 23 or _46 , but ___ = 6.5 . TS QR pi (pi) radius (radio) 2. △JNZ ~ △KOA. Find the unknown measures. (Lesson 4.2) J similar shapes (formas semejantes) A. Find the unknown side x. 2 is a factor of 14. Since 2 × 7 = 14, multiply 1 by 7 to find the value of x. M scale (escala) scale drawing (dibujo a escala) EXAMPLE 1 △NOP ~ △QRS. Find the unknown measures. 4 to find a factor of 14. Simplify __ 8 4 cm 2 cm : 14 ft Determine if the shapes are similar. (Lesson 4.1) $67.58 ESSENTIAL QUESTION NO ___ ___ = NP QR QS 4 __ x _ = 14 8 1 __ x _ = 14 2 1 ×7 __ _ = x 2 ×7 14 15 cm in the drawing equals 105 feet in the actual yard. Tim’s yard is 105 feet long. 4 cm in the drawing equals 28 feet in the actual yard. Tim’s yard is 28 feet wide. EXERCISES 8. A sporting goods store marks up the cost s of soccer balls by 250%. Write an expression that represents the retail cost of the soccer balls. The store buys soccer balls for $5.00 each. What is the retail price of the soccer balls? (Lesson 3.3) 1________ cm × 15 15 cm = _____ 7 ft × 15 105 ft Perimeter is twice the sum of the length and the width. So the perimeter of Tim’s yard is 2(105 + 28) = 2(133), or 266 feet. 7. The original price of a barbecue grill is $79.50. The grill is marked down 15%. What is the sale price of the grill? (Lesson 3.3) 1 cm in the drawing equals 7 feet in the actual yard. 1_______ cm × 4 4 cm = ____ 7 ft × 4 28 ft 6. Sam’s dog weighs 72 pounds. The vet suggests that for the dog’s health, its weight should decrease by 12.5 percent. According to the vet, what is a healthy weight 15 cm 2 cm 1 cm ____ = ____ 14 ft 7 ft Q 59° 14 cm N 8 cm 4 cm 86° y P 6 cm O R 12 cm S 86° 35° x Unit 2 143 144 x= 8.5 y= 17 r= 28° s= 62° 8 in. 62° N A y in. r 15 in. 28° x in. Z K s O 4 in. © Houghton Mifflin Harcourt Publishing Company (Lesson 3.2) ∠S and ∠P are corresponding angles. kilograms Unit 2 Ratios and Proportional Relationships 144 (Lesson 4.3) Unit 2 Performance Tasks (cont'd) 3 cm 3. In the scale drawing of a park, the scale is 1 cm: 10 m. Find the area of the actual park. 1.5 cm 450 m2 2. The table below shows how far several animals can travel at their maximum speeds in a given time. 1 cm : 10 m 4. The circumference of the larger circle is 15.7 yards. Find the circumference of the smaller circle. (Lesson 4.4) Animal Distances 4 yd 12.56 yd 5 yd Unit 2 Performance Tasks Animal Distance traveled (ft) Time (s) elk 33 giraffe 115 1 _ 2 2_12 zebra 117 2 a. Write each animal’s speed as a unit rate in feet per second. Elk: 66 ft/s 1. Landscape Architect A landscape architect creates a scale drawing of her plans for a garden. She draws the plans on a sheet of paper that measures 8_12 inches by 11 inches. On the righthand side of the paper, there is a column 2_12 inches wide that includes the company name and logo. The drawing itself is 5_12 inches by 7_21 inches. The scale of the drawing is 1 inch = 10 feet. CAREERS IN MATH Giraffe: 46 ft/s Zebra: 58.5 ft/s b. Which animal has the fastest speed? elk 2 12 in. c. How many miles could the fastest animal travel in 2 hours if it maintained the speed you calculated in part a? Use the formula d = rt and round your answer to the nearest tenth of a mile. Show your work. 5 12 in. 8 12 in. 66 ft/s ∙ 60 s = 3,960 ft; 3,960 ft ∙ 1 mi/5,280 = 0.75 7 12 in. mi/min; 0.75 mi/min ∙ 120 min = 90 miles; 90 miles a. The landscape architect wants to make a larger drawing on a sheet of paper that measures 11 inches by 17 inches. The larger drawing should include the same 2_12 inch column on the side. There should be at least _21 inch of space on all sides of the drawing. What are the dimensions of the area she can use to make the new drawing? d. The data in the table represents how fast each animal can travel at its maximum speed. Is it reasonable to expect the animal from part b to travel that distance in 2 hours? Explain why or why not. It is not reasonable. Sample answer: An animal probably 10 in. by 13.5 in. cannot travel at its maximum speed for 2 full hours. b. How large can she make the scale drawing without changing any of the proportions? Justify your reasoning. 9.9 in. by 13.5 in. The available area for the new drawing is 10 inches by 13.5 inches. If you increase the width of the drawing © Houghton Mifflin Harcourt Publishing Company © Houghton Mifflin Harcourt Publishing Company 11 in. from 5.5 inches to 10 inches, you must increase the length to about 13.63 in., which is longer than the 13.5 inches allowed. You can only increase the 7.5 inch length to 13.5 inches. Unit 2 145 146 Unit 2 Ratios and Proportional Relationships 146 UNIT 3 Probability and Statistics Additional Resources Personal Math Trainer my.hrw.com Online Assessment and Intervention Assessment Resources • Leveled Unit Tests: A, B, C, D • Performance Assessment Study Guide Review Vocabulary Development Integrating the ELPS Encourage English learners to refer to their notes and the illustrated, bilingual glossary as they review the unit content. c.4.E Read linguistically accommodated content area material with a decreasing need for linguistic accommodations as more English is learned. MODULE 5 Experimental Probability 7.6.A, 7.6.B, 7.6.C, 7.6.H, 7.6.I Key Concepts number of favorable outcomes • The probability of an event, or ______________________ , measures the likelihood that total number of possible outcomes the event will occur. (Lesson 5.1) • The probability of an event can be from 0 to 1, inclusive. (Lesson 5.1) • The experimental probability of an event can be found by comparing the number of times an event occurs to the total number of trials. (Lesson 5.2) • A compound event is an event that includes two or more simple events. (Lesson 5.3) MODULE 6 Experimental Probability 7.6.A, 7.6.D, 7.6.E, 7.6.H, 7.6.I Key Concepts • Theoretical probability is the probability that an event occurs when all the outcomes of the experiment are equally likely. (Lesson 6.1) • To find the theoretical probability, compare the number of ways the event can occur by the total number of equally likely outcomes. (Lesson 6.1) • The event with the higher probability, experimental or theoretical, is more likely to occur. (Lesson 6.3) 213 Unit 3 Review Study Guide MODULE ? 5 5. Christopher picked coins randomly from his piggy bank and got the numbers of coins shown in the table. Find each experimental probability. (Lessons 5.2, 5.3) Experimental Probability How can you use experimental probability to solve real-world problems? Senior Adult Young adult Child Female 5 8 2 14 Male 3 10 1 17 What is the experimental probability that his next new patient is a female adult? ( ) new patient is a of female adults __________________ P = number total number of patients female adult c. The next coin that Christopher picks is a penny or a nickel. © Houghton Mifflin Harcourt Publishing Company 8 2 = __ P = __ 15 60 P = _16 3. Picking a blue marble from a bag of 4 red marbles, 6 blue marbles, and 1 white marble. 6 P = __ 11 MODULE MODULE ? 6 Theoretical Probability theoretical probability (probabilidad teórica) How can you use theoretical probability to solve real-world problems? EXAMPLE 1 A. Lola rolls two fair number cubes. What is the probability that the two numbers Lola rolls include at least one 4 and have a product of at least 16? There are 5 pairs of numbers that include a 4 and have a product of at least 16: ) (4, 4), (4, 5), (4, 6), (5, 4), (6, 4) 31 P = __ 60 1 2 3 4 5 1 1 2 3 4 5 6 6 2 2 4 6 8 10 12 Find the probability. 3 3 6 9 12 15 18 number of possible ways 5 P = ______________________________ = ___ 4 4 8 12 16 20 24 36 5 5 10 15 20 25 30 B. Suppose Lola rolls the two number cubes 180 times. Predict how many times she will roll two numbers that include a pair of numbers like the ones described above. 6 6 12 18 24 30 36 total number of possible outcomes 2. Picking a 7 from a standard deck of 52 cards. A standard deck includes 4 cards of each number from 2 to 10. Key Vocabulary ESSENTIAL QUESTION new patient is number of children P = __________________ total number of patients a child EXERCISES Find the probability of each event. (Lesson 5.1) 1. Rolling a 5 on a fair number cube. 54 82 ___ < ___ ; more customers than usual brought their own bags. 100 124 sample space (expacio muestral) simulation (simulación) trial (prueba) 9 __ 23 6. A grocery store manager found that 54% of customers usually bring their own bags. In one afternoon, 82 out of 124 customers brought their own grocery bags. Did a greater or lesser number of people than usual bring their own bags? (Lesson 5.4) outcome (resultado (probabilidad)) probability (probabilidad) What is the experimental probability that his next new patient is a child? ( 6 6 __ 23 17 __ 23 b. The next coin that Christopher picks is not a quarter. simple event (suceso simple) EXAMPLE 2 For one month, a doctor recorded information about new patients as shown in the table. Quarter 8 compound event (suceso compuesto) experiment (experimento (probabilidad)) experimental probability (probabilidad experimental) number of red marbles P(picking a red marble) = _____________________ number of total marbles There are 2 red marbles. 2 __ = 7 The total number of marbles is 2 + 5 = 7. Dime 2 complement (complemento) event (suceso) EXAMPLE 1 What is the probability of picking a red marble from a jar with 5 green marbles and 2 red marbles? Nickel 7 a. The next coin that Christopher picks is a quarter. Key Vocabulary ESSENTIAL QUESTION Penny 4 1 = __ P = __ 52 13 One way to answer is to write and solve an equation. 5 × 180 = x ___ 4. Rolling a number greater than 7 on a 12-sided number cube. 36 25 = x 5 P = __ 12 © Houghton Mifflin Harcourt Publishing Company UNIT 3 Multiply the probability by the total number of rolls. Solve for x. Lola can expect to roll two numbers that include at least one 4 and have a product of 16 or more about 25 times. Unit 3 213 214 Unit 3 Probability and Statistics 214 EXAMPLE 2 A store has a sale bin of soup cans. There are 6 cans of chicken noodle soup, 8 cans of split pea soup, 8 cans of minestrone, and 13 cans of vegetable soup. Find the probability of picking each type of soup at random. Then predict what kind of soup a customer is most likely to pick. 7. Suppose you know that over the last 10 years, the probability that your town would have at least one major storm was 40%. Describe a simulation that you could use to find the experimental probability that your town will have at least one major storm in at least 3 of the next 5 years. (Lesson 6.4) Sample answer: Use whole numbers from 1 to 5. Let 1 and 2 represent 6 8 P(chicken noodle) = ___ P(split pea) = ___ 35 35 13 8 ___ P(vegetable) = ___ P(minestrone) = 35 35 The customer is most likely to pick vegetable soup. That is the event that has the greatest probability. a year with a major storm and 3, 4, and 5 represent a year without a major storm. Perform 10 trials by randomly generating 10 sets of 5 numbers. Count the sets that model 3 or more storms and divide by 10. EXERCISES Find the probability of each event. (Lessons 6.1, 6.2) 8 P = __ = _2 12 3 3. Tania flips a coin three times. The coin lands on heads twice and on tails once, not necessarily in that order. P = _3 8 2. Theo spins a spinner that has 12 equal sections marked 1 through 12. It does not land on 1. 1. 11 P = __ 12 CAREERS IN MATH Meteorologist A meteorologist predicts a 20% chance of rain for the next two nights, and a 75% chance of rain on the third night. a. On which night is it most likely to rain? On that night, is it likely to rain or unlikely to rain? 4. Students are randomly assigned two-digit codes. Each digit is either 1, 2, 3, or 4. Guy is given the number 11. 1 P = __ 16 the third night; likely b. Tara would like to go camping for the next 3 nights, but will not go if it is likely to rain on all 3 nights. Should she go? Use probability to justify your answer. Yes; the probability of its raining on all 3 nights is 0.2 ∙ 0.2 ∙ 0.75 = 5. Patty tosses a coin and rolls a number cube. (Lesson 6.3) 0.03, or only a 3% chance. It is very unlikely to rain on all 3 nights. a. Find the probability that the coin lands on heads and the cube lands on an even number. P = _1 2. Sinead tossed 4 coins at the same time. She did this 50 times, and 6 of those times, all 4 coins showed the same result (heads or tails). © Houghton Mifflin Harcourt Publishing Company 4 b. Patty tosses the coin and rolls the number cube 60 times. Predict how many times the coin will land on heads and the cube will land on an even number. a. Find the experimental probability that all 4 coins show the same result when tossed. 0.12 15 times b. Can you determine the experimental probability that no coin shows heads? Explain. 6. Rajan’s school is having a raffle. The school sold raffle tickets with 3-digit numbers. Each digit is either 1, 2, or 3. The school also sold 2 tickets with the number 000. Which number is more likely to be picked, 123 or 000? (Lesson 6.3) No; we aren't told how many times all tails came up. c. Suppose Sinead tosses the coins 125 more times. Use experimental probability to predict the number of times that all 4 coins will show heads or tails. Show your work. 000 © Houghton Mifflin Harcourt Publishing Company 1. Graciela picks a white mouse at random from a bin of 8 white mice, 2 gray mice, and 2 brown mice. Unit 3 Performance Tasks 125 ∙ 0.12 = 15 times Unit 3 215 216 Unit 3 Probability and Statistics 216 UNIT 4 Multiple Representations of Linear Relationships Additional Resources Personal Math Trainer my.hrw.com Online Assessment and Intervention Assessment Resources • Leveled Unit Tests: A, B, C, D • Performance Assessment Study Guide Review Vocabulary Development Integrating the ELPS Encourage English learners to refer to their notes and the illustrated, bilingual glossary as they review the unit content. c.4.E Read linguistically accommodated content area material with a decreasing need for linguistic accommodations as more English is learned. MODULE 7 Linear Relationships 7.7 Key Concepts • In a linear relationship, as one quantity changes by a constant amount, the other quantity also changes by a constant amount. (Lesson 7.1) • One way to describe a linear relationship is to write an equation in the form of y = mx + b, where m is the rate of change and b is the value of y when x is 0. (Lesson 7.2) MODULE 8 Equations and Inequalities 7.10.A, 7.10.B, 7.10.C, 7.11.A, 7.11.B Key Concepts • To solve a two-step equation or inequality, use inverse operations. (Lessons 8.1, 8.3) • Use substitution to check if a given value is a solution of an equation or inequality. (Lessons 8.2, 8.4) 271 Unit 4 Study Guide ? 7 3. Steve is saving for his daughter’s college education. He opens an account with $2,400 and deposits $40 per month. Represent the relationship using a table and an equation. (Lesson 7.2) Linear Relationships Months Savings ($) Key Vocabulary linear relationship (relación lineal) ESSENTIAL QUESTION y = 40x + 2,400 How can you use linear relationships to solve real-world problems? 4. Tonya has a 2-page story she wants to expand. She plans to write 3 pages per day until it is done. Represent the relationship using a table, an equation, and a graph. (Lesson 7.2) EXAMPLE Ross earns a set rate of $10 for babysitting, plus $6 per hour. Represent the relationship using a table, an equation, and a graph of the linear relationship. Amount ($) 0 $10 1 $16 2 $22 3 $28 4 $34 Days Total pages Babysitting Fees 40 Amount ($) Hours (2, 22) 16 8 Amount = $10 + $6 per hour O MODULE (1, 16) (0, 10) ? 2 4 6 Hours 8 3 11 12 8 4 (3, 11) (2, 8) (1, 5) (0, 2) O 2 4 8 6 Hours 8 10 Equations and Inequalities How can you use equations and inequalities to solve real-world problems? EXAMPLE 1 A clothing store sells clothing for 2 times the wholesale cost plus $10. The store sells a pair of pants for $48. How much did the store pay for the pants? Represent the solution on a number line. EXERCISES 1. The cost of a box of cupcakes is $1.50 per cupcake plus $3. Complete the table to represent the linear relationship. (Lesson 7.1) © Houghton Mifflin Harcourt Publishing Company 2 8 ESSENTIAL QUESTION 10 y = 10 + 6x Number of cupcakes 1 2 3 Let w represent the wholesale cost of the pants, or the price paid by the store. 2w + 10 = 48 4 2w = 38 $4.50 $6.00 $7.50 $9.00 Cost of cupcakes ($) w = 19 10 11 12 13 14 15 16 17 18 19 20 Subtract 10 from both sides. Divide both sides by 2. The store paid $19 for the pants. 2. The score a student receives on a standardized test based on the number of correct answer is shown in the table. Use the table to give a verbal description of the relationship between correct answers and score. (Lesson 7.1) Score 1 5 16 (3, 28) 24 Write an equation for the amount y in dollars earned for x hours. Correct answers 0 2 20 y = 3x + 2 (4, 34) 32 0 2 4 6 2,400 2,480 2,560 2,640 5 10 15 20 25 EXAMPLE 2 Determine which, if any, of these values makes the inequality -7x + 42 ≤ 28 true: x = -1, x = 2, x = 5. 210 220 230 240 250 −7(−1) + 42 ≤ 28 A student’s score is 200 plus 2 points per correct answer. x = 2 and x = 5 Unit 4 271 272 −7(2) + 42 ≤ 28 −7(5) + 42 ≤ 28 © Houghton Mifflin Harcourt Publishing Company MODULE Review Pages UNIT 4 Substitute each value for x in the inequality and evaluate the expression to see if a true inequality results. Unit 4 Multiple Representations of Linear Relationships 272 Unit 4 Performance Tasks 1. The cost of a ticket to an amusement park is $42 per person. For groups of up to 8 people, the cost per ticket decreases by $3 for each person in the group. Marcos’s ticket cost $30. Write and solve an equation to find the number of people in Marcos’s group. (Lessons 8.1, 8.2) 1. 42 - 3n = 30; n = 4 - 12 x=9 -8 -4 0 Spring Stretch 64 48 32 16 a. Write an equation for the line. Explain, using the graph and then using the equation, why the relationship is proportional. Solve each equation. Graph the solution on a number line. (Lesson 8.2) 2. 8x - 28 = 44 CAREERS IN MATH Mechanical Engineer A mechanical engineer is testing the amount of force needed to make a spring stretch by a given amount. The force y is measured in units called Newtons, abbreviated N. The stretch x is measured in centimeters. Her results are shown in the graph. Force (N) EXERCISES y = 8x; The graph is a straight line through the 4 8 O 2 4 6 8 10 Stretch (cm) origin, and therefore is a proportional relationship; the equation 12 is of the form y = kx, where k ≠ 0, and therefore is a proportional 3. -5z + 4 = 34 - 12 x = -6 -8 -4 relationship. 0 4 8 12 b. Identify the rate of change and the constant of proportionality. 8 N/cm; 8 4. Prudie needs $90 or more to be able to take her family out to dinner. She has already saved $30 and wants to take her family out to eat in 4 days. (Lesson 8.3) c. What is the meaning of the constant of proportionality in the context of the problem? Every centimeter of stretch of the spring requires 8 Newtons of force. a. Suppose that Prudie earns the same each day. Write an inequality to find how much she needs to earn each day. 2. A math tutor charges $30 for a consultation, and then $25 per hour. An online tutoring service charges $30 per hour. 30 + 4x ≥ 90 a. Does either service represent a proportional relationship? Explain. b. Suppose that Prudie earns $18 each day. Will she have enough money to take her family to dinner in 4 days? Explain. The online service represents a proportional relationship; the math Yes, x = 18 is a solution of the inequality. tutor’s charge does not. Sample answer: The equation representing Solve each inequality. Graph and check the solution. (Lesson 8.4) the cost of the online service is of the form y = kx, while the equation for the tutor is not. y>6 - 12 -8 -4 0 4 8 b. Write an equation for the cost c of h hours of tutoring for either service. Which service charges less for 4 hours of tutoring? Show your work. 12 math tutor: c = 30 + 25h; online service: c = 30h 6. 7x - 2 ≤ 61 For 4 hours, the math tutor charges = 30 + 25(4) = $130. The online x≤9 - 12 service charges c = 30(4) = $120. The online service charges less. -8 -4 0 4 8 © Houghton Mifflin Harcourt Publishing Company © Houghton Mifflin Harcourt Publishing Company 5. 15 + 5y > 45 12 Unit 4 273 274 Unit 4 Multiple Representations of Linear Relationships 274 UNIT 5 Geometric Relationships Additional Resources Personal Math Trainer my.hrw.com Online Assessment and Intervention Assessment Resources • Leveled Unit Tests: A, B, C, D • Performance Assessment Study Guide Review Vocabulary Development Integrating the ELPS Encourage English learners to refer to their notes and the illustrated, bilingual glossary as they review the unit content. c.4.E Read linguistically accommodated content area material with a decreasing need for linguistic accommodations as more English is learned. MODULE 9 Applications of Geometry Concepts 7.8.C, 7.9.B, 7.9.C, 7.11.C Key Concepts • The sum of the measures of a pair of complementary angles is 90°, and the sum of the measures of a pair of supplementary angles is 180°. (Lesson 9.1) • Vertical angles are the opposite angles formed by two intersecting lines which are congruent. (Lesson 9.1) • To find the circumference of a circle, or the distance around the circle, use the formula C = πd or C = 2πr. (Lesson 9.2) • To find the area of a circle, use the formula A = πr 2. (Lesson 9.3) MODULE 10 Volume and Surface Area 7.8.A, 7.9.A, 7.9.D Key Concepts • To find the volume of a prism, use the formula V = Bh, where B is the area of the base. (Lessons 10.1, 10.2) • To find the volume of a pyramid, use the formula V = __13 Bh, where B is the area of the base. (Lessons 10.1, 10.2) • The lateral surface area of a figure is the area of all the lateral, or side, faces of the figure. (Lesson 10.3) • The total surface area of a figure is the area of all the faces of the figure. (Lesson 10.3) 337 Unit 5 UNIT 5 Study Guide ? 9 Review Applications of Geometry Concepts ESSENTIAL QUESTION How can you apply geometry concepts to solve real-world problems? EXAMPLE 1 Find (a) the value of x and (b) the measure of ∠APY. a. ∠XPB and ∠YPB are supplementary. A 3. Key Vocabulary C ≈ 69.08 in., A ≈ 379.94 in2 adjacent angles (ángulos adyacentes) complementary angles (ángulos complementarios) congruent angles (ángulos congruentes) supplementary angles (ángulos suplementarios) C ≈ 28.26 m, A ≈ 63.59 m2 Find the area of each composite figure. Round to the nearest hundredth if necessary. (Lesson 9.4) 4. 5. 9 in. 9 in. 20 cm 13 in. vertical angles (ángulos opuestos por el vértice) 99 in2 Area 3x = 102° B MODULE MODULE x = 34° ? b. ∠APY and ∠XPB are vertical angles. m∠APY = m∠XPB = 3x = 102° 16 cm Area 420.48 cm2 Key Vocabulary lateral area (área lateral) lateral faces (cara lateral) ESSENTIAL QUESTION How can you use volume and surface area to solve real-world problems? net (plantilla) total surface area (área de superficie total) The figure is a rectangular pyramid. Volume = _13Bh ≈ 0.5(3.14)25 = _13(144)(8) ≈ 39.25 cm2 Area of rectangle = ℓw 6 cm Volume and Surface Area EXAMPLE The height of the figure whose net is shown is 8 feet. Identify the figure. Then find its volume, lateral area, and total surface area. Area of semicircle = 0.5(πr2) 10 cm 10 10 pyramid (pirámide) EXAMPLE 2 Find the area of the composite figure. It consists of a semicircle and a rectangle. © Houghton Mifflin Harcourt Publishing Company 4.5 m 22 in. 3x + 78° = 180° Y P 3x 78° X 2. Lateral Area () 4 _12 (12)(8) = 192 Total Surface Area = 384 The volume of the rectangular pyramid is 384 cubic feet, the lateral surface area is 192 square feet, and the total surface area is 336 square feet. = 10(6) = 60 cm2 8 ft 12 ft 192 + 122 = 192 + 144 = 336 © Houghton Mifflin Harcourt Publishing Company MODULE Find the circumference and area of each circle. Round to the nearest hundredth. (Lessons 9.2, 9.3) The area of the composite figure is approximately 99.25 square centimeters. EXERCISES EXERCISES 1. Identify the figure represented by the net. Then find its lateral area and total surface area. (Lesson 10.3) 1. Find the value of y and the measure of ∠YPS (Lesson 9.1) R 140° 5y P Y y= Z m ∠YPS = triangular prism 8° lateral area = 468 ft2 40° total surface area = 618 ft2 10 ft 15 ft 13 ft 13 ft 13 ft 13 ft S Unit 5 337 338 2. Unit 5 Geometric Relationships 338 Unit 5 Performance Tasks (cont'd) Find the volume of each figure. (Lessons 10.1, 10.2) 2. 3. b. How many square feet of material does Miranda need to make the tent (including the floor)? Show your work. 9m () 6m 5 in. 7 in. 2 c. What is the volume of the tent? Show your work. 4m ( _12 )(8)(6)( 9 _12 ) = 228 ft 36 m3 420 in3 ( ) ( 7 _14 )+ ( 9 _21 )(8) = 48 + 137.75 + 76 = 261.75 ft 2 _12 (8)(6) + 2 9 _12 12 in. d. Suppose Miranda wants to increase the volume of the tent by 10%. The specifications for the height (6 feet) and the width (8 feet) must stay the same. How can Miranda meet this new requirement? Explain. 4. The volume of a rectangular pyramid is 1.32 cubic inches. The height of the pyramid is 1.1 inches and the length of the base is 1.2 inches. Find the width of the base of the pyramid. (Lesson 10.1) 3 She will need to change the length, 9 _12 ft, so that the new volume is 3 in. ( 1__101 ) (228) = 250 _45 ft . That is ( _12 )(8)(6)ℓ = 250 _45, so ℓ = 10 __209 ft . 3 5. The volume of a triangular prism is 264 cubic feet. The area of a base of the prism is 48 square feet. Find the height of the prism. 2. Li is making a stand to display a sculpture made in art class. The stand will be 45 centimeters wide, 25 centimeters long, and 1.2 meters high. 5.5 ft (Lesson 10.2) a. What is the volume of the stand? Write your answer in cubic centimeters. 100 cm V = (45 cm)(25 cm)(1.2 m) _____ = 135,000 m ( Unit 5 Performance Tasks 1. Product Design Engineer Miranda is a product design engineer working for a sporting goods company. She designs a tent in the shape of a triangular prism. The dimensions of the tent are shown in the diagram. CAREERS IN MATH a. Draw a net of the triangular prism and label the dimensions. b. Li needs to fill the stand with sand so that it is heavy and stable. Each piece of wood is 1 centimeter thick. The boards are put together as shown in the figure, which is not drawn to scale. How many cubic centimeters 1.2 m of sand does she need to fill the stand? Explain how you found your answer. 1 7— 4 ft 6 ft ) 1 9— 2 ft 8 ft cm3 1 cm 1.2 m The dimensions of the interior of the © Houghton Mifflin Harcourt Publishing Company 1 ft 7— and (25 - 2) cm, because each 8 ft 4 25 cm Side View piece of wood is 1 cm thick. The 1 ft 7— 4 45 cm Front View © Houghton Mifflin Harcourt Publishing Company stand are (45 - 2) cm, (120 - 2) cm, 6 ft interior volume is V = (43 cm) 1 ft 9— 2 (118 cm)(23 cm) = 116,702 cm3. 6 ft Unit 5 339 340 Unit 5 Geometric Relationships 340 UNIT 6 Measurement and Data Additional Resources Personal Math Trainer my.hrw.com Online Assessment and Intervention Assessment Resources • Leveled Unit Tests: A, B, C, D • Performance Assessment Study Guide Review Vocabulary Development Integrating the ELPS Encourage English learners to refer to their notes and the illustrated, bilingual glossary as they review the unit content. c.4.E Read linguistically accommodated content area material with a decreasing need for linguistic accommodations as more English is learned. MODULE 11 Analyzing and Comparing Data 7.6.G, 7.12.A Key Concepts • Circle graphs and bar graphs represent data by showing portions of a set of data grouped by categories. (Lesson 11.1) • To compare dot plots, look at the shape, center, and spread of the dot plots. (Lesson 11.2) • To compare box plots, look at the median, interquartile range, and shape of the box plots. (Lesson 11.3) 393 Unit 6 MODULE 12 Random Samples and Populations 7.6.F, 7.12.B, 7.12.C Key Concepts • A random sample is a sample in which every member of your population has an equal chance at being selected. If a sample is not random, it is called a biased sample. (Lesson 12.1) • Dot plots and box plots can be used to represent data from a random sample and to make inferences about data from a random sample. (Lesson 12.2) • Random samples from two or more populations can be compared by comparing the dot and box plots representing the data. (Lesson 12.3) Unit 6 Performance Tasks The Performance Tasks provide students with the opportunity to apply concepts from this unit in real-world problem situations. CAREERS IN MATH For more information about careers in mathematics as well as various mathematics appreciation topics, visit the American Mathematical Society at www.ams.org CAREERS IN MATH Entomologist In Performance Task item 1, students can see how an entomologist uses mathematics on the job. SCORING GUIDES FOR PERFORMANCE TASKS 1. MATHEMATICAL PROCESSES Task 395 Unit 6 7.1.A, 7.1.E, 7.1.F, 7.1.G Possible Points (Total: 6) a 1 point for the correct medians of 11 for Type A and 11 for Type B, 1 point for the correct ranges of 4 for Type A and 10 for Type B, and 1 point for the correct interquartile ranges of 3 for Type A and 2 for Type B. b 1 point for the answer that range makes Type A appear more consistent, 1 point for the answer that interquartile range makes Type B appear more consistent, and 1 point for any reasonable choice and explanation, for example: Type A is actually more consistent because it has a much smaller range, while its IQR is only slightly larger. MODULE MODULE ? 11 11 Review Analyzing and Comparing Data EXERCISES 1. Five candidates are running for the position of School Superintendent. Find the percent of votes that each candidate received. (Lesson 11.1) Key Vocabulary Candidate A: 16.5%, Candidate B: 21%, circle graph (gráfica circular) Candidate C: 20%, Candidate D: 20.5%, ESSENTIAL QUESTION Candidate E: 22% How can you solve real-world problems by analyzing and comparing data? EXAMPLE 1 There are 500 students at Trenton Middle School. The percent of students in each grade level is shown in the circle graph. Calculate the number of students in each grade. 43% = 0.43 31% = 0.31 70 60 0 A B C D E Candidates Middle School Students by Grade 8th grade 26% 6th grade 43% 0 1 2 3 4 5 6 7 Time Online (h) 0.43 × 500 = 215 0.31 × 500 = 155 0.26 × 500 = 130 0 1 2 3 4 5 6 7 Time Reading (h) 2. Compare the shapes, centers, and spreads of the dot plots. 7th grade 31% Shape: Online: The data are clustered to the right. Reading: The data have two clusters, one at the left and one at the right. EXAMPLE 2 The box plots show the amount that each employee from the same office donated to two charities. Compare the shapes, centers and spreads of the box plots. Center: Online: The data have a single peak at 6. Reading: The data have two peaks, at 0 and 6. Spread: Online: The Charity A data are spread from 4 to 7 with an outlier at 0. Reading: The data are spread from 0 to 6 with a gap from 3 to 4. Charity B 3. Calculate the medians of the dot plots. Online: 8 12 16 20 24 28 32 36 40 44 48 52 © Houghton Mifflin Harcourt Publishing Company 80 The dot plots show the number of hours a group of students spend online each week, and how many hours they spend reading. Compare the dot plots visually. (Lesson 11.2) 26% = 0.26 There are 215 6th graders, 155 7th graders, and 130 8th graders. Votes 90 4. Calculate the ranges of the dot plots. Online: Shapes: The lengths of the boxes are similar, as are the overall lengths of the graphs. The whiskers for the two graphs are very different. The whiskers for Charity A are similar in length. The left whisker for Charity B is much shorter than the right one. The box plots show the math and reading scores on a standardized test for a group of students. Use the box plots shown to answer the following questions. (Lesson 11.3) Centers: The median for Charity A is $40, and for Charity B is $20. That means the median donor gave $20 more for Charity A. 6; Reading: 5 7; Reading: 6 © Houghton Mifflin Harcourt Publishing Company Study Guide Number of votes UNIT 6 Math Scores Reading Scores 2 4 6 8 10 12 14 16 18 20 22 5. Compare the maximum and minimum values of the box plots. Spreads: The interquartile range for Charity A is 44 - 32 = 12. The interquartile range for Charity B is slightly less, 24 - 14 = 10. The minimum value of both plots is 4, and the maximum of both plots is 20. 6. Compare the interquartile spread of the box plots. The donations varied more for Charity B and were lower overall. The interquartile range of the math scores is 14 - 6 = 8. The interquartile range of the reading scores is 18 - 10 = 8. Unit 6 393 394 Unit 6 Measurement and Data 394 MODULE MODULE ? 12 12 Random Samples and Populations ESSENTIAL QUESTION How can you use random samples and populations to solve real-world problems? 3. Mr. Puccia teaches Algebra 1 and Geometry. He randomly selected 10 students from each class. He asked the students how many hours they spend on math homework in a week. He recorded each set of data in a list. (Lesson 12.3) Algebra 1: 4, 0, 5, 3, 6, 3, 2, 1, 1, 4 Geometry: 7, 3, 5, 6, 5, 3, 5, 3, 6, 5 Key Vocabulary biased sample (muestra sesgada) population (población) random sample (muestra aleatoria) a. Make a dot plot for Algebra 1. Then find the mean and the range for Algebra 1. sample (muestra) 0 1 2 3 4 5 6 7 Algebra 1 mean = 2.9, range = 6 - 0 = 6 EXAMPLE An engineer at a lightbulb factory chooses a random sample of 100 lightbulbs from a shipment of 2,500 and finds that 2 of them are defective. How many lightbulbs in the shipment are likely to be defective? b. Make a dot plot for Geometry. Then find the mean and the range for Geometry. mean = 4.8, range = 7 - 3 = 4 defective lightbulbs defective lightbulbs in population _______________ = _________________________ size of sample size of population 2 x ___ = ____ 100 2,500 2 · 25 x ______ = ____ 100 · 25 2,500 c. What can you infer about the students in the Algebra 1 class compared to the students in the Geometry class? 0 1 2 3 4 5 6 7 Geometry Sample answer: The students in the Geometry class spend more time on math homework than the students in the Algebra class. x = 50 In a shipment of 2,500 lightbulbs, 50 are likely to be defective. Unit 6 Performance Tasks EXERCISES 1. 1. Molly uses the school directory to select at random 25 students from her school for a survey on which sports people like to watch on television. She calls the students and asks them, “Do you think basketball is the best sport to watch on television?” (Lesson 12.1) a. Did Molly survey a random sample or a biased sample of the students at her school? random Type A Type B 7 9 11 13 15 Number of Butterflies 17 a. Find the median, range, and interquartile range for each data set. b. Was the question she asked an unbiased question? Explain your answer. Type A: median = 11; range = 4; IQR = 3 Type B: median = 11; range = 10; IQR = 2 No. Sample answer: It assumes the person watches basketball on television. b. Which measure makes it appear that flower type A had a more consistent number of butterfly visits? Which measure makes it appear that flower type B did? If you had to choose one flower as having the more consistent visits, which would you choose? Explain your reasoning. 2. There are 2,300 licensed dogs in Clarkson. A random sample of 50 of the dogs in Clarkson shows that 8 have ID microchips implanted. How many dogs in Clarkson are likely to have ID microchips implanted? (Lesson 12.2) The range makes Type A appear more consistent. The interquartile 368 dogs © Houghton Mifflin Harcourt Publishing Company © Houghton Mifflin Harcourt Publishing Company CAREERS IN MATH Entomologist An entomologist is studying how two different types of flowers appeal to butterflies. The box-and-whisker plots show the number of butterflies who visited one of two different types of flowers in a field. The data were collected over a two-week period, for one hour each day. range makes Type B appear more consistent. Possible explanation: Type A is actually more consistent because it has a much smaller range, while its IQR is only slightly larger. Unit 6 395 396 Unit 6 Measurement and Data 396 UNIT 7 Personal Financial Literacy Additional Resources Personal Math Trainer my.hrw.com Online Assessment and Intervention Assessment Resources • Leveled Unit Tests: A, B, C, D • Performance Assessment Study Guide Review Vocabulary Development Integrating the ELPS Encourage English learners to refer to their notes and the illustrated, bilingual glossary as they review the unit content. c.4.E Read linguistically accommodated content area material with a decreasing need for linguistic accommodations as more English is learned. MODULE 13 Taxes, Interest, and Incentives 7.13.A, 7.13.E, 7.13.F Key Concepts • To find the tax on an item, multiply the amount of tax, written as a decimal, by the price of the item. (Lesson 13.1) • To calculate compound interest, use the formula A = P(1 + r) t. (Lesson 13.2) • Interest paid only on the principal is simple interest, while compound interest is interest paid on the principal and interest the account has earned. (Lesson 13.2) MODULE 14 Planning Your Future COMMON CORE 7.13.B, 7.13.C, 7.13.D Key Concepts • A budget is a plan to help you reach your financial goals and should consider fixed expenses and variable expenses. (Lessons 14.1, 14.2) • To calculate net worth, subtract liabilities, or debts you owe, from assets, or things you own. (Lesson 14.3) 451 Unit 7 Study Guide MODULE MODULE ? 13 13 Review Taxes, Interest, and Incentives 3. Bette has $10,000 to put into savings accounts. She puts half into an account that earns simple interest at an annual rate of 3.1%. She puts the other half into an account that earns interest at an annual rate of 2.6% compounded annually. After 10 years, which account will earn more money? How much more? (Lesson 13.2) Key Vocabulary the simple interest account; $86.86 compound interest (interés compuesto) federal withholding (retención fiscal federal) ESSENTIAL QUESTION 4. Barack can buy a four pack of mangos for $2.76 or a six pack of mangos for $4.32. Which is the better buy? Explain. (Lesson 13.3) gross pay (paga bruta) How can you solve real-world problems involving taxes, interest, and incentives? the four pack; the unit price of the four pack is $0.69, and the interest (interés) unit price of the six pack is $0.72. net pay (paga neta) sales tax (impuesto sobre la venta) EXAMPLE 1 Samuel puts $5,000 into a savings account that earns simple interest at an annual rate of 1.2% for 5 years. Tinos puts the same amount into a savings account that earns interest at an annual rate of 1.2% compounded annually for 5 years. Which account will earn more interest after 5 years? simple interest (interés simple) MODULE MODULE taxable income (ingreso sujeto a impuestos) Samuel Tinos Use the formula for simple interest. Use the formula for compound interest. 14 14 Planning Your Future assets (activos) ? ESSENTIAL QUESTION How can you use mathematics to plan for a successful financial future? I=P×r×t A = P(1 + r) A = $5,000(1.012)5 = $5,307.29 Samuel earns $300 in interest. Tinos earns $5,307.29 - $5,000 = $307.29. EXAMPLE 1 The circle graph shows the Morales family’s monthly budget. Their fixed expenses are housing, savings, and an emergency fund. Use the graph to find the amount the family spends on fixed expenses. t Budget for Morales Family / Net Monthly Income = $5,200 Tinos’s account will earn more interest than Samuel’s account. © Houghton Mifflin Harcourt Publishing Company 1. Find the sales tax for each product, using a sales tax rate of 8.5%. Then find the product’s total price and the total for the entire purchase. Round to the nearest hundredth. (Lesson 13.1) 2. Claire earns a monthly paycheck of $2,900. Federal withholding is 12.8% of her gross pay. Complete the table. (Lesson 13.1) Item Unit Price ($) Number Subtotal ($) Tax ($) Total ($) Basketball 8.95 3 26.85 2.28 29.13 Tennis balls (3 pack) 3.88 5 19.40 1.65 21.05 Total Gross Pay Transportation (car expense, bus passes) 8% $2,900 Clothing 6% Entertainment 4% $371.20 Social Security $179.80 Medicare $42.05 Net Pay income (ingreso) Item $2,306.95 Unit 7 451 452 net worth (patrimonio neto) planned savings (ahorros previstos) savings (ahorros) variable expense (gasto variable) Emergency fund 5% Housing cost (house payment and insurance) 32% Medical (insurance and additional expenses) 20% 50.18 Taxes Federal Income Tax budget (presupuesto) fixed expenses (gastos fijos) liabilities (pasivo) I = $5,000 × 0.012 × 5 = $300 EXERCISES Key Vocabulary Savings 10% Food 15% Percent Amount Available Housing cost 32% $1,664 Savings 10% $520 Emergency fund 5% $260 © Houghton Mifflin Harcourt Publishing Company UNIT 7 Unit 7 Personal Financial Literacy 452 Unit 7 Performance Tasks EXERCISES For 1–3, use the graph from the Example. (Lessons 14.1) 1. 1. How much money does the Morales family spend on clothing each month? $312 2. How much more money does the Morales family spend on food than on entertainment? $572 per month 3. The air conditioning in the Morales’s house is broken. The repair service estimated that the cost of repairing it is $1,040. How many months of emergency funds will the family use to fix the air conditioning? CAREERS IN MATH Freelance Computer Programmer Andre works as a freelance computer programmer, and his laptop has stopped working. He is purchasing a new laptop, which he needs to have in 2 days in order to meet a job deadline. He lives in Massachusetts, which has a 6.25% sales tax. He is considering these three options for the purchase: Buy it online for $1,499, pay sales tax, and pay $24 priority shipping. Buy it in Massachusetts for $1,479. Buy it in New Hampshire for $1,549 with no sales tax. 4 months a. Calculate the total cost for each option. Which is the best deal? 4. Mr. and Mrs. Clark have two children. They live in Waco, Texas. They may move to Austin to be closer to their parents. Their employers pay for 100% of one parent’s health insurance premium and 50% of the premium for other family members. Use an online family budget estimator to estimate to the nearest dollar, the following for the Clark family in Waco and in Austin. (Lesson 14.2) online: $1,616.69; Massachusetts: $1,571.44; New Hampshire: $1,549; Buying in New Hampshire is the best deal. b. List other factors that relate to the purchase that could also affect Andre’s decision. Online is the most convenient option; he can place his order without Answers may vary according to the online family estimator used. leaving his home, but he cannot try it before purchasing. Buying in Monthly Estimated Budget for Waco ($) Monthly Estimated Budget for Austin ($) Housing $629 $836 transportation. If he buys in Massachusetts, he can likely have the Food $491 $491 laptop within the hour, which allows him to get back to work quickly. Child Care $635 $841 Medical Insurance $301 $309 Medical Out-of-pocket $118 $118 Transportation $395 $482 Other Necessities $309 $360 Total monthly expenses $2,878 $3,437 Total Federal Tax Impact $−19 $200 $2,859 $3,637 $17 $22 Necessary monthly income Household Hourly Wage 5. Rashid paid off his car, which is worth $6,500. He has a credit card balance of $325. He has $4,250 in his savings account and $672 in his checking account. He owes $3,600 in student loans. He lives with his parents. What is Rashid’s net worth? (Lesson 14.3) New Hampshire means time spent driving or money to take public 2. Grant is going to purchase several large pizzas for a party. He has two options for local pizza shops as described below. Hank’s Pizza: For every two pizzas, get a third at half price. Antonio’s: 20% off of all orders of $40 or more. a. Write a paragraph that describes the other information Grant needs in order to compare these options. Include both facts that relate to the pizzas and facts that relate to the event. Grant needs to know the cost of a large pizza at each shop. He also needs to know how many pizzas he needs to purchase. He can determine this by dividing the number of people at the event by how many people one large pizza serves. © Houghton Mifflin Harcourt Publishing Company © Houghton Mifflin Harcourt Publishing Company Item b. Suppose large pizzas cost $13 at each shop. Compare the total cost at each shop for 3 pizzas and for 6 pizzas. 3 pizzas: $32.50 at Hank’s Pizza, $39 at Antonio’s; 6 pizzas: $65 at Hank’s Pizza, $62.40 at Antonio’s $7,497 Unit 7 453 454 Unit 7 Personal Financial Literacy 454
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