38. Elections A radio station asks its listeners to call and tell who their favorite candidate is in an upcoming election. Sixty-eight percent of the callers prefer a certain candidate, so the radio station announces that the candidate will win the election. Is the conclusion valid? Explain.

    C Challenge

39. Data Collection You want to find out what kinds of pets the families of students attending your school have.
    1. Write an unbiased question for your survey. Will you be collecting quantitative or qualitative data?
    2. Choose a population and sampling method. Describe them both.
    3. Collect the data as you described and display the results in a graph.
40. Writing A toothpaste company reports that four out of five dentists recommend their toothpaste. What information do you need to know about the survey to determine whether the results are unbiased?

Standardized Test Prep

SAT/ACT

41. What is the solution of the equation x 2 − 11 = 19 ? x over 2 , minus 11 equals 19 question mark
    1. 8
    2. 16
    3. 30
    4. 60
42. What is 0.0000212 written in scientific notation?
    6. 2.12 × 10 5 2.12 , times , 10 to the fifth
    7. 2.12 × 10 − 5 2.12 , times , 10 super negative 5 end super
    8. 21.2 × 10 − 6 21.2 , times , 10 super negative 6 end super
    9. 2.12 × 10 − 6 2.12 , times , 10 super negative 6 end super
43. 40%of what number is 50?
    1. 155
    2. 125
    3. 20
    4. 2

    Short Response

44. A reporter is trying to predict who will win an open seat on the city council. Her plan is to ask 20 coworkers who they think will win. Will this plan give a good sample? Explain.

Mixed Review

See Lesson 12-4.

45. Of 30 test scores, 12 are less than or equal to 85. What is the percentile rank of a test score of 85?
46. There are 15 bands in a competition. The judges give 9 bands a score of 7.5 or lower. What is the percentile rank of 7.5?

See Lesson 3-4.

Solve each inequality.

47. 4 − 3 a < 3 a − 2 4 minus 3 eh less than 3 eh minus 2
48. 3 ( x − 2 ) ≤ 6 x + 3 3 open x minus 2 close less than or equal to 6 x plus 3
49. 2.7 + 2 b > 3.4 − 1.5 b 2.7 plus 2 b greater than 3.4 minus 1.5 b

Get Ready! To prepare for Lesson 12-6, do Exercises 50–52.

See p. 789.

Write each fraction in simplest form.

50. 5 ⋅ 4 ⋅ 3 ⋅ 2 ⋅ 1 3 ⋅ 2 ⋅ 1 fraction 5 dot 4 dot 3 dot 2 dot 1 , over 3 dot 2 dot 1 end fraction
51. 7 ⋅ 6 ⋅ 5 ⋅ 4 ⋅ 3 ⋅ 2 ⋅ 1 5 ⋅ 4 ⋅ 3 ⋅ 2 ⋅ 1 fraction 7 dot 6 dot 5 dot 4 dot 3 dot 2 dot 1 , over 5 dot 4 dot 3 dot 2 dot 1 end fraction
52. 6 ⋅ 5 ⋅ 4 ⋅ 3 ⋅ 2 ⋅ 1 5 ⋅ 4 ⋅ 3 ⋅ 2 ⋅ 1 fraction 6 dot 5 dot 4 dot 3 dot 2 dot 1 , over 5 dot 4 dot 3 dot 2 dot 1 end fraction

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