Chapter 5: Normal Distributions

Test Bank

Multiple Choice

1. Normal distributions ______.

a. are based on data collected from populations

b. are based on mathematical formulas

c. consist of a small number of scores

d. are a figment of our imagination

Cognitive Domain: Knowledge

Answer Location: What are Normal Distributions?

Difficulty Level: Easy

2. One of the characteristics of a normal distribution is that it ______.

a. is based on data collected by researchers

b. consists of a small number of scores

c. is based on mathematical formulas

d. is a figment of our imagination

Cognitive Domain: Knowledge

Answer Location: What are Normal Distributions?

Difficulty Level: Easy

3. Normal distributions ______.

a. are skewed (asymmetrical)

b. contain an infinite number of scores

c. are bimodal

d. always consist of both positive and negative scores

Cognitive Domain: Knowledge

Answer Location: What are Normal Distributions?

Difficulty Level: Easy

4. ______ are distributions based on a population of an infinite number of scores calculated from a mathematical formula.

a. Frequency distribution

b. Normal distribution

c. Sample distribution

d. z-score distribution

Cognitive Domain: Knowledge

Answer Location: What are Normal Distributions?

Difficulty Level: Easy

5. Imagine this figure is designed to represent a normal distribution. What is one problem with it?

a. It does not contain an infinite number of scores.

b. It is too peaked.

c. It should be skewed.

d. It does not consist of both positive and negative scores

Cognitive Domain: Comprehension

Answer Location: What are Normal Distributions?

Difficulty Level: Medium

6. Imagine the figure is designed to represent a normal distribution. What’s one problem with it?

a. It should either be positively or negatively skewed.

b. It should be either a frequency polygon or a histogram.

c. The tails should not touch the X-axis.

d. It is too flat.

Cognitive Domain: Comprehension

Answer Location: What are Normal Distributions?

Difficulty Level: Medium

7. Figure A is an example of a ______ distribution; Figure B is an example of a ______ distribution.

Figure A

Figure B

a. normal; theoretical

b. theoretical; skewed

c. frequency; normal

d. normal; frequency

Cognitive Domain: Knowledge

Answer Location: Why are Normal Distributions Important?

Difficulty Level: Medium

8. This distribution

is an example of a ______.

a. theoretical distribution

b. normal distribution

c. standard normal distribution

d. frequency distribution

Cognitive Domain: Knowledge

Answer Location: Why are normal Distributions Important?

Difficulty Level: Medium

9. Normal distributions differ from frequency distributions in that ______.

a. normal distributions are based on data you have actually collected

b. frequency distributions are based on an infinite number of scores

c. normal distributions are based on mathematical formulas

d. frequency distributions are theoretical distributions

Cognitive Domain: Comprehension

Answer Location: Why are Normal Distributions Important?

Difficulty Level: Easy

10. One difference between normal distributions and frequency distributions is that ______.

a. normal distributions are based on fewer scores than frequency distributions

b. frequency distributions represent populations; normal distributions represent samples

c. normal distributions are more skewed than frequency distributions

d. normal distributions are hypothetical; frequency distributions are based on actual data

Cognitive Domain: Comprehension

Answer Location: Why are Normal Distributions Important?

Difficulty Level: Easy

11. One difference between normal distributions and frequency distributions is that ______.

a. normal distributions are based on fewer scores than frequency distributions

b. frequency distributions represent samples; normal distributions represent populations

c. normal distributions are more skewed than frequency distributions

d. normal distributions are based on actual data; frequency distributions are hypothetical

Cognitive Domain: Comprehension

Answer Location: Why are Normal Distributions Important?

Difficulty Level: Easy

12. One difference between frequency distributions and normal distributions is that ______.

a. frequency distributions represent populations; normal distributions represent samples

b. frequency distributions are hypothetical; normal distributions are based on actual data

c. only normal distributions are based on mathematical formulas

d. frequency distributions consist of a greater number of scores than normal distributions

Cognitive Domain: Comprehension

Answer Location: Why are Normal Distributions Important?

Difficulty Level: Easy

13. One difference between frequency distributions and normal distributions is that ______.

a. only frequency distributions are based on data collected by researchers

b. frequency distributions are based on formulas; normal distributions are based on data

c. frequency distributions are represented by parameters; normal distributions are represented by statistics

d. normal distributions are more likely to be skewed than frequency distributions

Cognitive Domain: Comprehension

Answer Location: Why are Normal Distributions Important?

Difficulty Level: Easy

14. Moving from learning about frequency distributions to learning about normal distributions coincides with moving from learning about ______ to learning about ______.

a. descriptive statistics; inferential statistics

b. central tendency; variability

c. statistical hypotheses; research hypotheses

d. statistical formulas; SPSS

Cognitive Domain: Comprehension

Answer Location: Why are Normal Distributions Important?

Difficulty Level: Easy

15. Moving from learning about frequency distributions to learning about normal distributions coincides with moving from learning about ______ to learning about ______.

a. how to collect data; how to analyze data

b. statistics used to describe data; statistics used to test hypotheses

c. parameters; statistics

d. independent variables; dependent variables

Cognitive Domain: Comprehension

Answer Location: Why are Normal Distributions Important?

Difficulty Level: Easy

16. Moving from learning about frequency distributions to learning about normal distributions coincides with moving from learning about ______ to learning about ______.

a. the research process; how to analyze data

b. how to collect data; mathematical formulas

c. measures of central tendency; measures of variability

d. describing samples; testing hypotheses about populations

Cognitive Domain: Comprehension

Answer Location: Why are Normal Distributions Important?

Difficulty Level: Medium

17. The differences between frequency distributions and normal distributions reflect the difference between ______ and ______.

a. descriptive statistics; inferential statistics

b. analyzing data; examining data

c. testing hypotheses; proving hypotheses

d. the mean; the standard deviation

Cognitive Domain: Comprehension

Answer Location: Why are Normal Distributions Important?

Difficulty Level: Easy

18. The ______ of a normal distribution is equal to ______.

a. mean; σ

b. standard deviation; μ

c. standard deviation; 0

d. standard deviation; σ

Cognitive Domain: Knowledge

Answer Location: Is There Only one Normal Distribution?

Difficulty Level: Medium

19. The ______ of a normal distribution is equal to ______.

a. mean; μ

b. standard deviation; 0

c. mean; 1

d. mean;

Cognitive Domain: Knowledge

Answer Location: Is There Only one Normal Distribution?

Difficulty Level: Medium

20. The ______ of the ______ is equal to ______.

a. mean; standard normal distribution; σ

b. standard deviation; normal distribution; μ

c. mean; standard normal distribution; 0

d. standard deviation; standard normal distribution; μ

Cognitive Domain: Knowledge

Answer Location: The Standard Normal Distribution

Difficulty Level: Medium

21. The ______ of ______ is equal to ______.

a. mean; the standard normal distribution; 1

b. standard deviation; the standard normal distribution; μ

c. mean; a normal distribution; 1

d. standard deviation; a normal distribution; 1

Cognitive Domain: Knowledge

Answer Location: The Standard Normal Distribution

Difficulty Level: Medium

22. ______ represents the ______ of a normal distribution.

a. σ; modality

b. ; modality

c. μ; variability

d. μ; modality

Cognitive Domain: Knowledge

Answer Location: Is There Only one Normal Distribution?

Difficulty Level: Medium

23. The ______ of a normal distribution is represented by ______.

a. symmetry; σ

b. modality; μ

c. modality; s

d. variability; μ

Cognitive Domain: Knowledge

Answer Location: Is There Only one Normal Distribution?

Difficulty Level: Medium

24. ______ represents the ______ of a normal distribution.

a. σ; modality

b. μ ; symmetry

c. μ ; variability

d. σ; variability

Cognitive Domain: Knowledge

Answer Location: Is There Only one Normal Distribution?

Difficulty Level: Medium

25. In the standard normal distribution, the mean is equal to ______ and the standard deviation is equal to ______.

a. 1; 0

b. 0; 0

c. 0; 1

d. 1; 1

Cognitive Domain: Knowledge

Answer Location: The Standard Normal Distribution

Difficulty Level: Medium

26. Normal distributions are an important concept to researchers because they ______.

a. are based on data collected from samples

b. help researchers evaluate scores on variables

c. consist of a small number of scores

d. help define ‘normal’ and ‘abnormal’ behavior

Cognitive Domain: Comprehension

Answer Location: Why are Normal Distributions Important?

Difficulty Level: Easy

27. Normal distributions are an important concept to researchers because ______.

a. there is only one normal distribution

b. they do not actually exist

c. they are the basis of statistical techniques used by researchers

d. they help define ‘normal’ and ‘abnormal’ behavior

Cognitive Domain: Comprehension

Answer Location: Why are Normal Distributions Important?

Difficulty Level: Easy

28. Normal distributions are an important concept to researchers because ______.

a. they are the basis of statistical techniques designed to test hypotheses

b. researchers typically collect data from entire populations

c. there is only one normal distribution

d. they are neither peaked nor flat

Cognitive Domain: Comprehension

Answer Location: Why are Normal Distributions Important?

Difficulty Level: Easy

29. Inferential statistics (statistics used to test research hypotheses) assume that ______.

a. variables are normally distributed in the population

b. variables are measured in z-scores

c. researchers collect data from people with normal personalities

d. researchers collect data from populations rather than from samples

Cognitive Domain: Knowledge

Answer Location: Is There Only One Normal Distribution?

Difficulty Level: Easy

30. The ‘assumption of normality’ refers to ______.

a. the shape of the distribution for a variable

b. people’s behavior and personality

c. descriptive statistics

d. the nature of the relationship between samples and populations

Cognitive Domain: Knowledge

Answer Location: Is There Only one Normal Distribution?

Difficulty Level: Easy

31. The belief that many variables are normally distributed in the population ______.

a. is only true when populations are very small

b. is referred to as the ‘assumption of normality’

c. is the basis behind descriptive statistics

d. has been proven to be false

Cognitive Domain: Knowledge

Answer Location: Is There Only One Normal Distribution?

Difficulty Level: Easy

32. One problem in using normal distributions is that ______.

a. how you interpret a score depends on how the variable is measured

b. there is only one normal distribution

c. they are skewed (asymmetric)

d. they do not actually exist

Cognitive Domain: Comprehension

Answer Location: Is There Only One Normal Distribution?

Difficulty Level: Easy

33. One problem in using normal distributions is that ______.

a. how you interpret a score depends on how a variable is measured

b. the sum of deviations from the mean is always equal to zero

c. they’re based on a small number of scores

d. the use of the word ‘normal’ is seen as politically incorrect

Cognitive Domain: Comprehension

Answer Location: Is There Only One Normal Distribution?

Difficulty Level: Easy

34. Except for ______, the standard normal distribution is similar to other normal distributions.

a. the symmetry of the distribution

b. the shape of the distribution

c. the total number of scores of the distribution

d. the unit of measurement of the distribution

Cognitive Domain: Comprehension

Answer Location: What Is the Standard Normal Distribution?

Difficulty Level: Medium

35. Compared with other normal distributions, the standard normal distribution is similar in terms of ______.

a. the mean of the distribution

b. the standard deviation of the distribution

c. the unit of measurement of the distribution

d. the total number of scores in the distribution

Cognitive Domain: Comprehension

Answer Location: What Is the Standard Normal Distribution?

Difficulty Level: Easy

36. In which of the following ways is the standard normal distribution similar to other normal distributions?

a. the unit of measurement

b. the total number of scores in the distribution

c. the mean of the distribution

d. none of these

Cognitive Domain: Comprehension

Answer Location: What Is the Standard Normal Distribution?

Difficulty Level: Easy

37. In which of the following ways is the standard normal distribution (normal curve) similar to other normal distributions?

a. the standard deviation of the distribution

b. the symmetry of the distribution

c. the unit of measurement

d. none of these

Cognitive Domain: Comprehension

Answer Location: What Is the Standard Normal Distribution?

Difficulty Level: Easy

38. The standard normal distribution differs from other normal distributions in that only the standard normal distribution ______.

a. is measured in standard deviation units

b. consists of an infinite number of scores

c. is bell-shaped

d. is based on mathematical formulas

Cognitive Domain: Comprehension

Answer Location: What Is the Standard Normal Distribution?

Difficulty Level: Easy

39. In which of the following ways is the standard normal distribution different from other normal distributions?

a. the mean of the distribution

b. the standard deviation of the distribution

c. the unit of measurement of the distribution

d. all of these

Cognitive Domain: Application

Answer Location: What Is the Standard Normal Distribution?

Difficulty Level: Easy

40. Standard normal distribution scores are also known as ______.

a. frequencies

b. normal scores

c. z-scores

d. standard scores

Cognitive Domain: Application

Answer Location: What Is the Standard Normal Distribution?

Difficulty Level: Easy

41. The ______ of the standard normal distribution is equal to ______.

a. mean; σ

b. standard deviation; 0

c. standard deviation; μ

d. mean; 0

Cognitive Domain: Knowledge

Answer Location: Interpreting z-Scores: Distance From the Mean

Difficulty Level: Medium

42. The ______ of the standard normal distribution (normal curve) is equal to ______.

a. mean; σ

b. standard deviation; 1

c. mean;

d. standard deviation; σ

Cognitive Domain: Knowledge

Answer Location: Interpreting z-Scores: Distance from the Mean

Difficulty Level: Medium

43. About ______ of z-scores in the standard normal distribution are within ±1 standard deviations of the mean.

a. one-third

b. half

c. two-thirds

d. 95%

Cognitive Domain: Knowledge

Answer Location: Finding the Area Between two z-Scores

Difficulty Level: Medium

44. About ______ of z-scores in the standard normal distribution are within ______ standard deviations of the mean.

a. half; ±3

b. two-thirds; ±1

c. 95%; ±1

d. 99%; ±2

Cognitive Domain: Knowledge

Answer Location: Finding the Area Between Two z-Scores

Difficulty Level: Medium

45. About ______ of z-scores in the standard normal distribution are between the z-scores ±1.96.

a. one-third

b. half

c. two-thirds

d. 95%

Cognitive Domain: Knowledge

Answer Location: Finding the Area Between Two z-Scores

Difficulty Level: Medium

46. About ____ of z-scores in the standard normal distribution are within ±2 standard deviations of the mean.

a. one-fourth

b. half

c. two-thirds

d. 95%

Cognitive Domain: Knowledge

Answer Location: Finding the Area Between Two z-Scores

Difficulty Level: Medium

47. About ______ of z-scores in the standard normal distribution are within ______ standard deviations of the mean.

a. 99%; ±1

b. half; ±2

c. two-thirds; ±3

d. 95%; ±2

Cognitive Domain: Knowledge

Answer Location: Finding the Area Between Two z-Scores

Difficulty Level: Medium

48. About ______ of z-scores in the standard normal distribution are within ______ standard deviations of the mean.

a. 99%; ±3

b. half; ±1

c. two-thirds; ±2

d. 95%; ±1

Cognitive Domain: Knowledge

Answer Location: Finding the Area Between Two z-Scores

Difficulty Level: Medium

49. Roughly ______ of z-scores in the standard normal distribution are within ±3 standard deviations of the mean.

a. one-third

b. half

c. two-thirds

d. all

Cognitive Domain: Knowledge

Answer Location: Finding the Area Between Two z-Scores

Difficulty Level: Medium

50. Roughly all of the z-scores in the standard normal distribution are with in ______ standard deviations of the mean.

a. ±1

b. ±1.96

c. ±2

d. ±3

Cognitive Domain: Knowledge

Answer Location: Finding the Area Between Two z-Scores

Difficulty Level: Medium

51. “Your score is about three-fourths of a standard deviation above the mean.” Which of the following statements is most accurate?

a. Your z-score is .71.

b. Your z-score is .34.

c. Your z-score is –.77.

d. You cannot estimate your z-score with the information provided.

Cognitive Domain: Application

Answer Location: Interpreting z-Scores: Relative Position Within the Distribution

Difficulty Level: Medium

52. “Your score is about a standard deviation above the mean.” Which of the following statements is most accurate?

a. Your z-score is –.97.

b. Your z-score is 34.13%.

c. Your z-score is .94.

d. You cannot estimate your z-score with the information provided.

Cognitive Domain: Application

Answer Location: Interpreting z-Scores: Relative Position Within the Distribution

Difficulty Level: Medium

53. “Your score is around two standard deviations above the mean.” Which of the following statements is MOST accurate?

a. Your z-score is 95%.

b. Your z-score is –2.06.

c. Your z-score is 1.94.

d. You cannot estimate your z-score with the information provided.

Cognitive Domain: Application

Answer Location: Interpreting z-Scores: Relative Position Within the Distribution

Difficulty Level: Medium

54. “Your score is almost two standard deviations above the mean.” Which of the following statements is MOST accurate?

a. Your z-score is 1.80.

b. Your z-score is 2.05.

c. Your z-score is -1.80.

d. Your z-score is 2.05.

Cognitive Domain: Application

Answer Location: Interpreting z-Scores: Relative Position Within the Distribution

Difficulty Level: Medium

55. “Your z-score is in the top 5% of the class.” Which of the following statements is MOST accurate?

a. Your z-score is 5.

b. Your z-score is 2.

c. Your z-score is 0.

d. Your z-score is 1.

Cognitive Domain: Application

Answer Location: Interpreting z-Scores: Relative Position Within the Distribution

Difficulty Level: Medium

56. “Your score on this variable is about two-thirds of a standard deviation below the mean.” Which of the following statements is MOST accurate?

a. Your z-score is .67.

b. Your z-score is –.23.

c. Your z-score is –.65.

d. You cannot estimate your z-score with the information provided.

Cognitive Domain: Application

Answer Location: Interpreting z-Scores: Relative Position Within the Distribution

Difficulty Level: Medium

57. “Your score on this variable is about one-half of a standard deviation below the mean.” Which of the following statements is MOST accurate?

a. Your z-score is 1.51.

b. Your z-score is -1.47.

c. Your z-score is -.53.

d. You cannot estimate your z-score with the information provided.

Cognitive Domain: Application

Answer Location: Interpreting z-Scores: Relative Position Within the Distribution

Difficulty Level: Medium

58. “Your score is about a standard deviation below the mean.” Which of the following statements is MOST accurate?

a. Your z-score is -.93.

b. Your z-score is 1.04.

c. Your z-score is -.36.

d. Your z-score is 95%.

Cognitive Domain: Application

Answer Location: Interpreting z-scores: Relative Position Within the Distribution

Difficulty Level: Medium

59. “Your score is about half a standard deviation below the mean.” Which of the following statements is MOST accurate?

a. Your z-score is .54.

b. Your z-score is –.19.

c. Your z-score is –.47.

d. Your z-score is -20%.

Cognitive Domain: Application

Answer Location: Interpreting z-Scores: Relative Position Within the Distribution

Difficulty Level: Medium

60. “Your z-score on the exam is in the bottom 15% of the class.” Which of the following statements is MOST accurate?

a. Your z-score is –1.10.

b. Your z-score is –15.

c. Your z-score is –15%.

d. Your z-score is –.25.

Cognitive Domain: Application

Answer Location: Interpreting z-Scores: Relative Position Within the Distribution

Difficulty Level: Medium

61. What z-score designates or marks the bottom 20% of the standard normal distribution?

a. –.20

b. ±.26

c. ±.52

d. –.84

Cognitive Domain: Application

Answer Location: Interpreting z-Scores: Relative Position Within the Distribution

Difficulty Level: Medium

62. What percentage of z-scores in the standard normal distribution are less than z = .80?

a. 21.19%

b. 28.81%

c. 57.62%

d. 78.81%

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a z-Score

Difficulty Level: Hard

63. What percentage of z-scores in the standard normal distribution are less than z = .20?

a. 42.07%

b. 57.93%

c. 84.00%

d. 92.07%

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a z-Score

Difficulty Level: Hard

64. What percentage of z-scores in the standard normal distribution are less than z = 1.45?

a. 7.35%

b. 42.65%

c. 92.65%

d. 42.51%

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a z-Score

Difficulty Level: Hard

65. What percentage of z-scores in the standard normal distribution are less than z = 2.36?

a. .91%

b. 49.09%

c. 50.91%

d. 99.09%

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a z-Score

Difficulty Level: Hard

66. What percentage of z-scores in the standard normal distribution are less than z = –1.25?

a. 1.25%

b. 10.56%

c. 60.56%

d. 89.44%

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a z-Score

Difficulty Level: Hard

67. What percentage of z-scores in the standard normal distribution are less than z = –.25?

a. 9.87%

b. -40.13%

c. 40.13%

d. 90.13%

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a z-Score

Difficulty Level: Hard

68. What percentage of z-scores in the standard normal distribution are less than z = –.35?

a. 13.68%

b. 36.32%

c. 63.68%

d. 86.32%

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a z-Score

Difficulty Level: Hard

69. What percentage of z-scores in the standard normal distribution are less than z = –1.03?

a. –15.15%

b. 15.15%

c. 34.85%

d. 65.15%

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a z-Score

Difficulty Level: Hard

70. What percentage of z-scores in the standard normal distribution are greater than z = .65?

a. .65%

b. 24.22%

c. 25.78%

d. 74.22%

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a z-Score

Difficulty Level: Hard

71. What percentage of z-scores in the standard normal distribution are greater than z = 1.11?

a. 1.11%

b. 13.35%

c. 36.65%

d. 86.65%

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a z-Score

Difficulty Level: Hard

72. What percentage of z-scores in the standard normal distribution are greater than z = –2.00?

a. 2.28%

b. 52.28%

c. 84.00%

d. 97.72%

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a z-Score

Difficulty Level: Hard

73. What percentage of z-scores in the standard normal distribution are greater than z = –1.40?

a. 8.08%

b. 41.92%

c. 58.08%

d. 91.92%

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a z-Score

Difficulty Level: Hard

74. What percentage of z-scores in the standard normal distribution are greater than z = –1.03?

a. 15.15%

b. 34.85%

c. 65.15%

d. 84.85%

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a z-Score

Difficulty Level: Hard

75. What percentage of z-scores in the standard normal distribution are between z = –.20 and z = .40?

a. 7.53%

b. 23.07%

c. 42.07%

d. 76.93%

Cognitive Domain: Application

Answer Location: Finding the Area Between two z-Scores

Difficulty Level: Hard

76. What percentage of z-scores in the standard normal distribution are between z = –.25 and z = .15?

a. 3.91%

b. 9.87%

c. 15.83%

d. 40.13%

Cognitive Domain: Application

Answer Location: Finding the Area Between two z-Scores

Difficulty Level: Hard

77. What percentage of z-scores in the standard normal distribution are between z = –.40 and z = .25?

a. 9.87%

b. 15.54%

c. 25.41%

d. 34.46%

Cognitive Domain: Application

Answer Location: Finding the Area Between two z-Scores

Difficulty Level: Hard

78. What percentage of z-scores in the standard normal distribution are between z = –.33 and z = .33?

a. 00.00%

b. 12.93%

c. 25.86%

d. 37.07%

Cognitive Domain: Application

Answer Location: Finding the Area Between two z-Scores

Difficulty Level: Hard

79. The shaded area in this distribution most closely represents ______.

a. the % of z-scores between .00 and –1.72

b. the % of z-scores less than 1.49

c. the % of z-scores greater than –1.34

d. the % of z-scores less than –1.28

Cognitive Domain: Application

Answer Location: Finding the Area Between two z-Scores

Difficulty Level: Hard

80. The shaded area in this distribution is most likely to represent ______.

a. the % of z-scores between the mean and .75

b. the % of z-scores less than .75

c. the % of z-scores less than –.75

d. the % of z-scores greater than .75

Cognitive Domain: Application

Answer Location: Finding the Area Between two z-Scores

Difficulty Level: Hard

81. The shaded areas in this distribution most closely represents ______.

a. 80% of all z-scores

b. the % of z-scores between the mean and 3.00

c. the % of z-scores less or greater than ± .25

d. the % of z-scores less or greater than ± 2.00

Cognitive Domain: Application

Answer Location: Finding the Area Between two z-Scores

Difficulty Level: Hard

82. The shaded areas in this distribution most closely represents ______.

a. 60% of all z-scores

b. the % of z-scores between .75 and 2.00

c. the % of z-scores greater than 2.00

d. the % of z-scores between the mean and 2.00

Cognitive Domain: Application

Answer Location: Finding the Area Between two z-Scores

Difficulty Level: Hard

83. The shaded area in this distribution most closely represents ______.

a. 55% of all z-scores

b. the % of z-scores between –.70 and –2.03

c. the % of z-scores between .80 and 1.98

d. the % of z-scores less than –2.01

Cognitive Domain: Application

Answer Location: Finding the Area Between two z-Scores

Difficulty Level: Hard

84. The shaded area in this distribution most closely represents ______.

a. the % of z-scores between –.80 and 2.00

b. the % of z-scores less than –.90

c. the % of z-scores greater than 2.00

d. the % of z-scores between .80 and –2.00

Cognitive Domain: Application

Answer Location: Finding the Area Between two z-Scores

Difficulty Level: Hard

85. The shaded area in the distribution most closely represents ______.

a. the % of z-scores greater than .40

b. the % of z-scores less than –.80

c. the % of z-scores between –.75 and .35

d. the % of z-scores between .80 and –1.00

Cognitive Domain: Application

Answer Location: Finding the Area Between two z-Scores

Difficulty Level: Hard

86. The shaded area in the distribution most closely represents ______.

a. the % of z-scores greater than .40

b. the % of z-scores between .80 and –.80

c. the % of z-scores less than 3.00

d. the % of z-scores between .66 and –2.25

Cognitive Domain: Application

Answer Location: Finding the Area Between two z-Scores

Difficulty Level: Hard

87. A variable is normally distributed with a hypothesized population mean of 20 and a standard deviation of 4. What percentage of scores are greater than 23?

a. 77.34%

b. 75.00%

c. 27.34%

d. 22.66%

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a Score

Difficulty Level: Hard

88. A variable is normally distributed with a hypothesized population mean of 30 and a standard deviation of 4. What percentage of scores are greater than 37?

a. 1.75%

b. 4.01%

c. 45.99%

d. 51.75%

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a Score

Difficulty Level: Hard

89. A variable is normally distributed with a hypothesized population mean of 40 and a standard deviation of 8. What percentage of scores are less than 46?

a. 77.34%

b. 75.00%

c. 27.34%

d. 22.66%

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a Score

Difficulty Level: Hard

90. For a variable that is normally distributed with a mean of 150 and a standard deviation of 25, approximately ______ of the scores are between ______ and ______.

a. 95%; 125 and 175

b. 95%; 100 and 200

c. 68%; 100 and 200

d. 99%; 125 and 175

Cognitive Domain: Application

Answer Location: Finding the Area Between Two Scores

Difficulty Level: Hard

91. For a variable that is normally distributed with a mean of 100 and a standard deviation of 25, approximately ______ of the scores are between ______ and ______.

a. 68%; 75 and 125

b. 68%; 50 and 150

c. 95%; 100 and 150

d. 95%; 100 and 200

Cognitive Domain: Application

Answer Location: Finding the Area Between Two Scores

Difficulty Level: Hard

92. For a variable that is normally distributed with a mean of 60 and a standard deviation of 10, approximately ______ of the scores are between ______ and ______.

a. 95%; 40 and 80

b. 95%; 50 and 70

c. 68%; 40 and 80

d. 99%; 40 and 80

Cognitive Domain: Application

Answer Location: Finding the Area Between Two Scores

Difficulty Level: Hard

93. For a variable that is normally distributed with a mean of 50 and a standard deviation of 5, approximately ______ of the scores are between ______and ______.

a. 95%; 45 and 55

b. 95%; 40 and 60

c. 68%; 40 and 60

d. 95%; 35 and 65

Cognitive Domain: Application

Answer Location: Finding the Area Between Two scores

Difficulty Level: Hard

94. For a variable that is normally distributed with a mean of 20 and a standard deviation of 4, approximately ______ of the scores are between ______and ______.

a. 95%; 16 and 24

b. 68%; 10 and 30

c. 68%; 12 and 28

d. 99%; 8 and 32

Cognitive Domain: Application

Answer Location: Finding the Area Between Two Scores

Difficulty Level: Hard

95. If a variable is normally distributed with a mean of 30 and a standard deviation of 6, approximately ______ of the scores are between ______and ______.

a. 68%; 24 and 36

b. 95%; 6 and 54

c. 68%; 12 and 48

d. 99%; 24 and 36

Cognitive Domain: Application

Answer Location: Finding the Area Between Two Scores

Difficulty Level: Hard

96. Imagine the average score on this exam ends up being 71 with a standard deviation of 10. If scores are normally distributed, ______ is the lowest score that would place you in the top 20% of the class.

a. 71

b. 76

c. 80

d. 84

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a Score

Difficulty Level: Hard

97. Imagine the average score on this exam ends up being 77 with a standard deviation of 5. If scores are normally distributed, ______ is the lowest score that would place you in the top 10% of the class.

a. 70

b. 78

c. 82

d. 84

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a Score

Difficulty Level: Hard

98. A variable is normally distributed with a hypothesized population mean of 30 and a standard deviation of 6. What is the z-score for a raw score (X) of 40?

a. z = -1.67

b. z = 1.67

c. z = 4.75

d. z = 45.25

Cognitive Domain: Application

Answer Location: Understanding the z-Score Formula

Difficulty Level: Hard

99. A variable is normally distributed with a hypothesized population mean of 53 and a standard deviation of 9. What is the z-score for a raw score (X) of 46?

a. z = -.78

b. z = .78

c. z = 21.77

d. z = 28.23

Cognitive Domain: Application

Answer Location: Understanding the z-Score Formula

Difficulty Level: Hard

100. If a variable is normally distributed with a hypothesized mean (μ) of 32 and a standard deviation (σ) of 5, what is the z-score for a raw score (X) of 41?

a. z = 1.80

b z = -1.80

c. z = 46.41

d. z = 9

Cognitive Domain: Application

Answer Location: Understanding the z-Score Formula

Difficulty Level: Hard

101. If a variable is normally distributed with a hypothesized mean (μ) of 26 and a standard deviation (σ) of 7, what is the z-score for a raw score (X) of 21?

a. z = .71

b z = -.71

c. z = .90

d. z = 1.57

Cognitive Domain: Application

Answer Location: Understanding the z-Score Formula

Difficulty Level: Hard

102. IQ scores based on the Wechsler Adult Intelligence Scale (WAIS) are assumed to be normally distributed with a mean of 100 and a standard deviation of 15. What is the z-score for an IQ of 125?

a. z = –1.25

b. z = 1.25

c. z = 1.67

d. z = 5.05

Cognitive Domain: Application

Answer Location: Understanding the z-Score Formula

Difficulty Level: Hard

103. IQ scores based on the Wechsler Adult Intelligence Scale are assumed to be normally distributed with a mean of 100 and a standard deviation of 15. What is the z-score for an IQ of 90?

a. z = –.67

b. z = .67

c. z = –10

d. z = 12.67

Cognitive Domain: Application

Answer Location: Understanding the z-Score Formula

Difficulty Level: Hard

104. “Imagine you are president of a toy company that builds video games. You have determined that the time needed to build these games is normally distributed with a mean of 20 minutes and a standard deviation of 5 minutes.” What percentage of video games are built in LESS than 15 minutes?

a. 15.87%

b. 19.15%

c. 34.13%

d. 84.13%

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a Score

Difficulty Level: Hard

105. “Imagine you are president of a toy company that builds video games. You have determined that the time needed to build these games is normally distributed with a mean of 20 minutes and a standard deviation of 5 minutes.” 5% of the video games (the bottom 5%) take less than ______ minutes to build.

a. 1.65

b. 11.80

c. 20

d. 28.20

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a Score

Difficulty Level: Hard

106. “The records of the National Weather Service indicate that, on the average, the city of San Jose receives 14.03 inches of rain each year, with a standard deviation of 5.19 inches.” In what percentage of years would you expect there to be less than 12 inches of rain?

a. –.39%

b. 15.17%

c. 34.83%

d. 65.17%

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a Score

Difficulty Level: Hard

107. “The records of the National Weather Service indicate that, on the average, the city of San Jose receives 14.03 inches of rain each year, with a standard deviation of 5.19 inches.” How many inches of rain must fall for a year to be in the top 10%?

a. 6.64

b 10.38

c. 15.33

d. 20.67

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a Score

Difficulty Level: Hard

108. “IQ scores based on the Wechsler Adult Intelligence Scale are assumed to be normally distributed with a mean of 100 and a standard deviation of 15.” What percentage of adults have IQ scores less than 90?

a. 24.86%

b 25.14%

c. 74.86%

d. 75.14%

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a Score

Difficulty Level: Hard

109. “IQ scores based on the Wechsler Adult Intelligence Scale are assumed to be normally distributed with a mean of 100 and a standard deviation of 15.” What percentage of adults have IQ scores between 95 and 110?

a. 12.93%

b 25.14%

c. 37.07%

d. 37.79%

Cognitive Domain: Application

Answer Location: Finding the Area Between two Scores

Difficulty Level: Hard

110. “IQ scores based on the Wechsler Adult Intelligence Scale are assumed to be normally distributed with a mean of 100 and a standard deviation of 15.” The label ‘Genius’ is given to people whose IQ scores are 2 standard deviations above the mean. What IQ score do people need to have to be labeled a ‘Genius’?

a. 70

b. 85

c 115

d. 130

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a Score

Difficulty Level: Hard

111. “According to the National Center for Health Statistics, in 2005 the average birthweight of a newborn baby was approximately normally distributed with a mean of 119 ounces (7 lb, 7 oz) and a standard deviation of 19 ounces.” What percentage of babies weighed more than 128 ounces (8 lb) at birth?

a. .47%

b. 18.08%

c 31.92%

d. 81.92%

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a Score

Difficulty Level: Hard

112. “According to the National Center for Health Statistics, in 2005 the average birthweight of a newborn baby was approximately normally distributed with a mean of 119 ounces (7 lb, 7 oz) and a standard deviation of 19 ounces.” A ‘low birthweight’ baby is one who weighs less than 88 ounces (5 lb, 8 oz) at birth. What percentage of babies are low birthweight?

a. 5.16%

b 44.84%

c. 55.16%

d. 94.84%

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a Score

Difficulty Level: Hard

113. “According to the National Center for Health Statistics, in 2005 the average birthweight of a newborn baby was approximately normally distributed with a mean of 119 ounces (7 lb, 7 oz) and a standard deviation of 19 ounces.” What percentage of babies weigh between 112 and 144 ounces (7 and 9 lb) at birth?

a. 9.34%

b. 14.43%

c. 44.91%

d. 55.09%

Cognitive Domain: Application

Answer Location: Finding the Area Between Two Scores

Difficulty Level: Hard

114. “A recent study of Greek children estimated that the average weight of a 10-year old boy was 81.57 pounds with a standard deviation of 17.41 pounds (Papadimitriou et al., 2006).” What percentage of boys weigh more than 105 pounds?

a. 1.35%

b. 8.85%

c. 58.85%

d. 91.15%

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a Score

Difficulty Level: Hard

115. “A recent study of Greek children estimated that the average weight of a 10-year old boy was 81.57 pounds with a standard deviation of 17.41 pounds (Papadimitriou et al., 2006).” What percentage of boys weigh between 70 and 90 pounds?

a. 6.10%

b. 24.54%

c. 42.98%

d. 68.44%

Cognitive Domain: Application

Answer Location: Finding the Area Between Two Scores

Difficulty Level: Hard

116. “A study examining people’s water consumption estimated men spend an average of 10.4 minutes taking a shower, with a standard deviation of 4.8 minutes (Shimokura et al., 1998).” What percentage of men spend more than 15 minutes taking a shower?

a. .96%

b. 16.85%

c. 33.15%

d. 83.15%

Cognitive Domain: Application

Answer Location: Finding the Area Less or Greater Than a Score

Difficulty Level: Hard

117. “A study examining people’s water consumption estimated men spend an average of 10.4 minutes taking a shower, with a standard deviation of 4.8 minutes (Shimokura et al., 1998).” What percentage of men spend between 10 and 20 minutes taking a shower?

a. 44.53%

b. 47.26%

c. 50.91%

d. 53.19%

Cognitive Domain: Application

Answer Location: Finding the Area Between Two Scores

Difficulty Level: Hard

118. For a sample of raw scores, you calculate a mean of 15.25 and a standard deviation of 3.19. What is the z-score for a raw score of 11?

a. 1.09

b. 1.33

c. –.51

d. –1.33

Cognitive Domain: Application

Answer Location: Standardizing a Frequency Distribution

Difficulty Level: Hard

119. You can apply the normal curve table to a standardized distribution ______.

a. if the population standard deviation (σ) is known

b. when your sample is small

c. if the population mean (µ) is known

d. when the distribution of raw scores is normally distributed

Cognitive Domain: Comprehension

Answer Location: Characteristics of Standardized Distributions

Difficulty Level: Medium

120. An instructor transforms her students’ scores on a midterm into standardized (z) scores. Which of the following is by definition true about the distribution of standardized scores?

a. The standardized distribution is normally distributed.

b. The mean of the standardized scores is equal to 0.

c. The distribution of standardized scores stretches to infinity in both directions.

d. The standard deviation of the standardized scores is equal to σ.

Cognitive Domain: Comprehension

Answer Location: Characteristics of Standardized Distributions

Difficulty Level: Medium

121. An instructor transforms her students’ scores on a midterm into standardized (z) scores. The distribution of standardized scores ______.

a. is not necessarily symmetrical

b. has a mean of σ

c. has a standard deviation of μ

d. consists of an infinite number of scores

Cognitive Domain: Comprehension

Answer Location: Characteristics of Standardized Distributions

Difficulty Level: Medium

122. An instructor transforms her students’ scores on a midterm into standardized (z) scores. Which of the following is by definition true about the distribution of standardized scores?

a. The distribution is normally distributed.

b. The mean of the standardized scores is equal to μ.

c. The shape of the distribution of standardized scores is identical to the distribution of midterm scores.

d. The distribution contains an infinite number of scores.

Cognitive Domain: Comprehension

Answer Location: Characteristics of Standardized Distributions

Difficulty Level: Medium

True/False

1. There is only one normal distribution.

Cognitive Domain: Knowledge

Answer Location: Is There Only one Normal Distribution?

Difficulty Level: Easy

2. If two variables are normally distributed the shapes of both distributions will always be the same.

Cognitive Domain: Knowledge

Answer Location: Is There Only one Normal Distribution?

Difficulty Level: Easy

3. In the standard normal distribution, the mean is equal to 0 and the standard deviation is equal to 1.

Cognitive Domain: Knowledge

Answer Location: The Standard Normal Distribution

Difficulty Level: Easy

4. The larger the sample, the more likely the data will resemble a normal distribution.

Cognitive Domain: Knowledge

Answer Location: When Can You Apply the Normal Curve Table to a Standardized Distribution

Difficulty Level: Easy

5. Scores for the standard normal distribution are known as z scores.

Cognitive Domain: Knowledge

Answer Location: What Is the Standard Normal Distribution?

Difficulty Level: Easy