45.
/////ERROR ANALYSIS/////
Below is a bonus question that appeared on an algebra
test and a student’s response.
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q
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The student did not receive the bonus points. Why is this proportion incorrect?
Multiple Choice For Exercises 46 and 47, choose the best answer.
46. One day the U.S. dollar was worth approximately 100 Japanese yen. An exchange of
2500 yen was made that day. What was the value of the exchange in dollars?
$25
$2,400
$2,500
$270,000
47. Which proportion can be used to find 14% of 60?
60
60
x =_
x =_
14
14 = _
_
_
_
x
100 14
100
100 60
x
14 = _
_
100 60
48. Gridded Response Raul surveyed 35 students about their preferred lunch.
Fourteen preferred chicken. Half of those students preferred chicken with barbecue
sauce. What percent should Raul report as preferring chicken with barbecue sauce?
CHALLENGE AND EXTEND
49. Geometry Complementary angles are two angles whose measures add to 90°. The
ratio of the measures of two complementary angles is 4 : 5. What are the measures of
the angles?
50. Population The population density of Jackson, Mississippi, is 672.2 people per
square kilometer. What is the population density in people per square meter? Show
that your answer is reasonable. (Hint: There are 1000 meters in 1 kilometer. How
many square meters are in 1 square kilometer?)
Find each value. Round to the nearest tenth if necessary.
51. What percent of 16 is 2.75?
52. 22 is 73.5% of what number?
3 =_
5 is equivalent to
53. Reasoning Without using cross products, show that _
x
x-1
3(x - 1) = 5x.
SPIRAL STANDARDS REVIEW
7AF2.1,
Evaluate each expression. (Lesson 1-4)
55. (-3)3
54. 8 2
2.0,
4.0
5
()
1
57. - _
2
56. (-3)2
Write the power represented by each geometric model. (Lesson 1-4)
58.
59.
60.
È
Þ
È
Þ
È
Þ
Solve each equation. Check your answer. (Lesson 2-4)
61. 2x - 12 = 5x + 3
62. 3a - 4 = 6 - 7a
63. 3x - 4 = 2x + 4
2- 5 Solving Proportions
107