Lesson 9.1.1
NAME: ______________________________ DATE: _________________
9-10. Estimate the circumference or diameter for each of the following circles. For each one,
give your reasoning.
a. The diameter is 1 cm. What is the circumference?
b. The diameter is 7.2 meters. What is the circumference?
c. The circumference is 1 mile. What is the diameter?
d. The circumference is 12 inches. What is the diameter?
9-11. Imagine that you and your team will be conducting a survey to see how many minutes
long lunch should be at your school. Students understand that the longer lunch is, the longer the
school day is. Since you cannot ask every student, you will take a sample.
a. You ask every tenth student leaving a school-wide assembly to stop and think about
how long he or she would like lunch to be. Do you think this sample is representative of
the whole school?
b. These are the answers, in minutes, from the first 20 students:
60 40 50 25 30 15 30 50 50 35 45 25 25 50 25 60 55 60 60 15
Make an inference(a statistical prediction) about the average length all students at your
school think lunch should be.
9-12. Sasha saved $850 from her summer job last summer. She put it in an account that earns
simple interest each month. After 9 months, her account is worth $1003. What percent interest
did she earn each month?
Lesson 9.1.1
NAME: ______________________________ DATE: _________________
9-13. Copy the axes below and complete the scales.
a.
b.
9-14. Janet sells erasers at a price of 8 erasers for 60 cents. She started this table to show the
price for different numbers of erasers.
Erasers
$
8
0.60
4
1
12
10
16
100
a. Complete her table.
b .Does this situation represent a proportional relationship? Why or why not?
c. Use the information in the table to find the cost of 144 erasers. Write and solve a
proportion, if appropriate.
9-15. Jack has 120 songs on his music player. Some are rock, some are jazz, and the rest are
classical pieces. If his music player is on random shuffle mode, the probability that it will play
2
1
a classical piece is 5 and the probability that it will play a jazz piece is 3. How many songs of
each type are on Jack’s music player?
Lesson 9.1.1
NAME: ______________________________ DATE: _________________
9-16. Find the circumference of each of the circles described below.
a. Radius of 3 inches
b. Diameter of 27 cm
9-17. The table below shows a list of sampling methods. From what populations are these
samples taken? Write down the actual population for each of these sampling techniques.
Method of Sampling
Call every hundredth name in the phone
book.
Description of
Actual Population
People with phones who have their
number listed.
Call people at home at 10 a.m.
Ask every tenth person who leaves the mall.
Ask people leaving the bank.
Mail questionnaires to people.
Ask everyone on the school bus.
9-18. A pair of shoes originally costs $42 but is on sale for 33% off. What is the new
price? Show how you know.
Lesson 9.1.1
NAME: ______________________________ DATE: _________________
9-19. The students at Dolan Middle School are competing in after-school activities in which
they earn points for helping out around the school. Each team consists of the 30 students in a
homeroom. Halfway through the competition, the scores from the students in two of the teams
were displayed in the plots at right.
The champion team is the one with the most points when the scores of the 30 students on the
team are added. Which team would you rather be on? Explain.
9-20. Copy each problem. Then find the sum, difference, product, or quotient. Remember to
show all of your steps.
a. 23.6 + 12
b. 16.5 + 54.43
c. 46.21 − 31.2
d. 27.5 − 13.11
e. 4.5(6)
f. 55 ÷ 2
9-21. Review the definitions of complementary, supplementary, and vertical angles. Use the
information to answer the following questions.
a. Two angles are complementary. If one measures 65º, what is the measure of the other angle?
b. Two angles are supplementary. If one measures 125º, what is the measure of the other
angle?
Lesson 9.1.1
NAME: ______________________________ DATE: _________________
c. Two angles are vertical. If one measures 63º, what is the measure of the other angle?