Behavioral Sciences STAT 2nd Edition by Gary Heiman - Test Bank

Behavioral Sciences STAT 2nd Edition by Gary Heiman – Test Bank

 

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Sample Questions Are Posted Below

 

 

Multiple Choice
1. Which of the following is not one of the things the relative frequency of z-scores allows us to calculate for corresponding raw scores?
a. Relative frequency
b. Percentile
c. Comparison against other variables
d. Values in terms of goodness or badness

ANSWER: d
DIFFICULTY: Moderate
REFERENCES: p. 69
Understanding z-Scores
KEYWORDS: relative frequency

2. Chris wants to calculate a z­score for his own height. The average height in the class is 66 inches, and Chris’s height
is 62 inches. Chris calculated his z­score to be +1.5. What’s wrong with his calculation?
a. The z-score is an inappropriate calculation here.
b. The z-score should be a higher number.
c. He didn’t have the standard deviation.
d. The z-score should be a negative number.

ANSWER: d
DIFFICULTY: Moderate
REFERENCES: p. 70
Understanding z-Scores
KEYWORDS: z-score

3. Pat’s last statistics test score was 72. If the instructor tells Pat the grade distribution was approximately normal, the
class mean was 67, and the standard deviation was 3, which of the following is correct?
a. A score of 72 is never good.
b. Pat should be worried about this score, because many other students did better.
c. Pat should be fairly happy about this score, because many students did not do as well.
d. Pat should be ecstatic, because this is obviously one of the highest grades in the class.

ANSWER: c
DIFFICULTY: Difficult
REFERENCES: p. 70
Understanding z-Scores
KEYWORDS: z-score

4. A z­score communicates a raw score’s
a. absolute magnitude.
b. distance from the mean in standard deviations.
c. direction from the standard deviation.
d. variability.

ANSWER: b DIFFICULTY: Easy REFERENCES: p. 70
Understanding z-Scores
KEYWORDS: z-score

5. In sampling distributions, all the samples contain sets of raw scores
a. with the same variance.
b. from the same population.
c. with the same mean.
d. that are representative of the population mean.

ANSWER: b
DIFFICULTY: Moderate
REFERENCES: pp. 72-73
Using the z-Distribution to Interpret Scores
KEYWORDS: sampling distribution

6. In a z-distribution, the standard deviation will always be
a. greater than 1.
b. less than 1.
c. equal to 1.
d. equal to 0.

ANSWER: c DIFFICULTY: Easy REFERENCES: p. 73
Using the z-Distribution to Interpret Scores
KEYWORDS: standard deviation

7. To evaluate a person for possible brain damage, a neuropsychologist gives the person a visual memory test and a
reading test. To compare the person’s performance across these two tests, what should the neuropsychologist do?
a. Graph the raw score distribution for each test on the same graph.
b. Calculate a z-score for each test.
c. Calculate z-scores for the sample means.
d. Find the simple frequency of the person’s raw score for each test.

ANSWER: b DIFFICULTY: Easy REFERENCES: p. 73
Using the z-Distribution to Interpret Scores
KEYWORDS: compare variabless

8. A z-score of zero always means
a. the raw score does not exist.
b. the raw score exists, but is negligible.
c. the raw score almost never occurs.
d. the raw score is equal to the mean.

ANSWER: d DIFFICULTY: Easy REFERENCES: p. 73
Using the z-Distribution to Interpret Scores
KEYWORDS: z-score

9. Given a normal distribution, as z­scores’ absolute values increase, those z-scores and the raw scores that correspond to them occur
a. more frequently.
b. less frequently.
c. more frequently at first and then less frequently.
d. less frequently at first and then more frequently.

ANSWER: b DIFFICULTY: Easy REFERENCES: pp. 73-74
Using the z-Distribution to Interpret Scores
KEYWORDS: z-score

10. The distribution of z-scores is always
a. positively skewed.
b. negatively skewed.
c. the same shape as the distribution of raw scores.
d. more spread out than the distribution of raw scores.

ANSWER: c
DIFFICULTY: Moderate
REFERENCES: p. 74
Using the z-Distribution to Compare Different Variables
KEYWORDS: distribution

11. When two normal z-distributions are plotted on the same graph, what can we say about the relative frequency of each z-score?
a. It will always be the same.
b. It will always be different.
c. It depends on the raw score mean.
d. It depends on the raw score standard deviation.

ANSWER: a DIFFICULTY: Easy REFERENCES: pp. 74-75
Using the z-Distribution to Compare Different Variables
KEYWORDS: relative frequency

12. We can use the standard normal curve as our model for
a. perfectly normal distributions only.
b. perfectly normal distributions only, when transformed to z-scores.
c. any approximately normal distribution, when transformed to z-scores.
d. any approximately normal distribution, when transformed to percentiles.

ANSWER: c DIFFICULTY: Easy REFERENCES: p. 75
Using the z-Distribution to Compute Relative Frequency
KEYWORDS: standard normal curve

13. For any approximately normal distribution, how can we find the relative frequency of the scores?
a. Convert the raw scores to z-scores and then use the standard normal curve.
b. Draw a graph of the raw scores and approximate the area under the curve.
c. Convert the raw scores to z-scores and then use the standard error of the mean.
d. Draw a graph of the raw scores and then use the standard error of the mean.

ANSWER: a DIFFICULTY: Easy REFERENCES: p. 75
Using the z-Distribution to Compute Relative Frequency
KEYWORDS: approximate normal distribution

14. z-scores can be calculated from
a. any data.
b. interval or ratio scores.
c. nominal or ordinal scores.
d. the range.

ANSWER: b
DIFFICULTY: Moderate
REFERENCES: p. 75
Using the z-Distribution to Compute Relative Frequency
KEYWORDS: z-score

15. The mean of the sampling distribution of means is always
a. greater than the population mean.
b. less than the population mean.
c. equal to the population mean.
d. the population mean divided by the square root of N.

ANSWER: c DIFFICULTY: Easy REFERENCES: p. 80
Using z-Scores to Describe Sample Means
KEYWORDS: sampling distribution of means

16. Which of the following statements accurately describes the sampling distribution of means?
a. The distribution of several sample means when an infinite number of samples of the same size N are selected from one raw score population.
b. The distribution of all possible sample means when a given finite number of samples of the same size N are selected from one raw score population.
c. The distribution of all possible sample means when an infinite number of samples of variously sized Ns are selected from several raw score populations.
d. The distribution of all possible sample means when an infinite number of samples of the same size N are selected from one raw score population.

ANSWER: d
DIFFICULTY: Moderate
REFERENCES: pp. 80-81
Using z-Scores to Describe Sample Means
KEYWORDS: sampling distribution of means

17. Sampling distributions of means are always
a. approximately normally distributed.
b. positively skewed.
c. negatively skewed.
d. more variable than the population from which the samples were drawn.

ANSWER: a
DIFFICULTY: Moderate
REFERENCES: pp. 80-81
Using z-Scores to Describe Sample Means
KEYWORDS: sampling distribution of means

18. Your relative standing informs you
a. of how your scores compares with the sample or population from which it is derived.
b. of the significance of your score.
c. whether your score is from a sample or a population.
d. of surprisingly very little.

ANSWER: a DIFFICULTY: Easy REFERENCES: p. 69
Understanding z-Scores
KEYWORDS: relative standing

19. Sally’s z-score on a given measure is -2.5, where the population mean is 5 and the standard deviation is 1.5. What is Sally’s raw score?
a. 1.25
b. 14 c. 3.5 d. 8.75
ANSWER: a
DIFFICULTY: Difficult
REFERENCES: p. 71
Understanding z-Scores
KEYWORDS: Computing raw score from z-score

20. You should first transform X to z in all of the following cases except if you seek
a. X that marks a given relative frequency beyond X in tail.
b. percentile of an X above the mean.
c. percentile of an X below the mean.
d. relative frequency of scores beyond X in tail.

ANSWER: a
DIFFICULTY: Difficult
REFERENCES: p. 78
Using the z-Distribution to Compute Relative Frequency
KEYWORDS: using the z-table

21. Another term for the standard deviation of the sampling distribution of means is known as
a. the standard error of the mean.
b. the central limit theorem.
c. relative frequency.
d. the sampling distribution of means.

ANSWER: a DIFFICULTY: Easy REFERENCES: p. 81
Using z-Scores to Describe Sample Means
KEYWORDS: the standard error of the mean

22. The central limit theorem is particularly helpful in terms of understanding the basic nature of
a. normal distributions.
b. statistical significance.
c. measurement error.
d. statistical association.

ANSWER: a DIFFICULTY: Easy REFERENCES: p. 80
Using z-Scores to Describe Sample Means

23. Suppose the population mean of some measure is 6 and the population standard deviation is 12. For a sample of 36, what is the standard error of the mean?
a. 2
b. 1 c. 1/6 d. 1/2
ANSWER: a
DIFFICULTY: Moderate
REFERENCES: p. 81
Using z-Scores to Describe Sample Means
KEYWORDS: standard error of the mean

Subjective Short Answer
24. For a distribution with = 50 and = 5, find the z-score for a raw score of 65.
ANSWER: 3
DIFFICULTY: Moderate
REFERENCES: p. 70
Understanding z-Scores
KEYWORDS: z-score

25. The sample mean for a recent introductory psychology test was 78, and the sample variance was 9. If a student
received a score of 82, what was this student’s z-score?
ANSWER: 1.33
DIFFICULTY: Moderate
REFERENCES: p. 70
Understanding z-Scores
KEYWORDS: z-score

26. For the following set of scores, what is the z-score for a raw score of 23?

22, 23, 19, 25, 26, 22, 19, 25
22, 20, 21, 23, 23, 24, 18, 20,
22, 24, 21, 21, 20, 24, 22, 21,
23
ANSWER: 0.50
DIFFICULTY: Difficult
REFERENCES: p. 70
Understanding z-Scores
KEYWORDS: z-score

27. For a distribution with = 50 and = 5, find the z-score for a raw score of 50.
ANSWER: 0 DIFFICULTY: Easy REFERENCES: p. 70
Understanding z-Scores
KEYWORDS: z-score

28. Jason’s z-score for his time in the 10-K race was −3. If the raw score standard deviation was 5 and the mean running time for the competitors was 55 minutes, what was his raw score?
ANSWER: 40 minutes DIFFICULTY: Moderate REFERENCES: p. 71
Understanding z-Scores
KEYWORDS: raw score

29. For a distribution with = 50 and = 5, find the raw score for z­score of –1.2.
ANSWER: 44.00
DIFFICULTY: Moderate
REFERENCES: p. 71
Understanding z-Scores
KEYWORDS: raw score

30. For a distribution with = 50 and = 5, find the raw score for z-score of +2.6.
ANSWER: 63.00
DIFFICULTY: Moderate
REFERENCES: p. 71
Understanding z-Scores
KEYWORDS: raw score

31. The sample mean for a recent introductory psychology test was 78, and the sample variance was 9. If a student’s z- score = –2.0, what was this student’s raw test score?
ANSWER: 72
DIFFICULTY: Moderate
REFERENCES: p. 71
Understanding z-Scores
KEYWORDS: raw score

32. If raw scores ranging from 1 to 50 represented all the corresponding negative z-scores on the distribution, and raw scores ranging from 50 to 100 represented all the corresponding positive z-scores, what would be the total relative frequency of 50 to 100?
ANSWER: 0.50
DIFFICULTY: Moderate
REFERENCES: p. 73
Using the z-Distribution to Interpret Scores
KEYWORDS: relative frequency

33. If there were 500 students in Jamal’s class, approximately how many actual students scored higher than Jamal on
the quiz if Jamal had a z-score of −1?
ANSWER: 420
DIFFICULTY: Difficult
REFERENCES: p. 73
Using the z-Distribution to Interpret Scores
KEYWORDS: z-score
34. Using the appropriate values from the z-table, find the area for scores greater than z = +0.89. ANSWER: 0.1867
DIFFICULTY: Easy
REFERENCES: p. 77
Using the z-Distribution to Compute Relative Frequency
KEYWORDS: area

35. What raw score is at the 34th percentile (34.13 to be exact) when the mean of the distribution is 50 and the standard deviation is 4?
ANSWER: 46
DIFFICULTY: Moderate
REFERENCES: p. 77
Using the z-Distribution to Compute Relative Frequency
KEYWORDS: raw score

36. For a z-score of 2.53, what is the area between the mean and the z-score? ANSWER: 0.4943
DIFFICULTY: Moderate
REFERENCES: pp.77-78
Using the z-Distribution to Compute Relative Frequency
KEYWORDS: area

37. For a z-score of 0.63, what is the area beyond the z-score in the tail?
ANSWER: 0.2643
DIFFICULTY: Moderate
REFERENCES: pp. 77-78
Using the z-Distribution to Compute Relative Frequency
KEYWORDS: area

38. For a z-score of 2.80, what is the area beyond the z-score in the tail?
ANSWER: 0.0026
DIFFICULTY: Moderate
REFERENCES: pp.77-78
Using the z-Distribution to Compute Relative Frequency
KEYWORDS: area

39. What is the area below a z-score of 1.40?
ANSWER: 0.9192
DIFFICULTY: Moderate
REFERENCES: pp.77-78
Using the z-Distribution to Compute Relative Frequency
KEYWORDS: area

40. What is the area above a z­score of –0.48?
ANSWER: 0.6844
DIFFICULTY: Moderate
REFERENCES: pp.77-78
Using the z-Distribution to Compute Relative Frequency
KEYWORDS: area

41. What is the area above a z-score of 1.96?
ANSWER: 0.0250
DIFFICULTY: Moderate
REFERENCES: pp.77-78
Using the z-Distribution to Compute Relative Frequency
KEYWORDS: area

42. If your sense of direction, relative to a sample of college students, gave you a z-score of +1.5, what is your percentile?
ANSWER: 93rd
DIFFICULTY: Difficult
REFERENCES: pp.77-78
Using the z-Distribution to Compute Relative Frequency
KEYWORDS: percentile

43. If only the upper 30% of a normally distributed class passed a quiz for which the mean was 70 and the standard deviation was 10, what was the lowest score a student could have received and still have passed?
ANSWER: 75.2
DIFFICULTY: Difficult
REFERENCES: pp.77-78
Using the z-Distribution to Compute Relative Frequency
KEYWORDS: percentile

44. For the following set of scores, what is the percentile for a score of 24?

22, 23, 19, 25, 26, 22, 19, 25
22, 20, 21, 23, 23, 24, 18, 20,
22, 24, 21, 21, 20, 24, 22, 21,
23
ANSWER: 84th
DIFFICULTY: Difficult
REFERENCES: pp.77-78
Using the z-Distribution to Compute Relative Frequency
KEYWORDS: percentile

45. A sampling distribution of means for samples of students taking the SAT exam has a population mean of 500 and a standard error of 200. What proportion of sample means would fall between the population mean and a sample mean of 800?
ANSWER: 0.4332
DIFFICULTY: Difficult
REFERENCES: pp.77-78
Using the z-Distribution to Compute Relative Frequency
KEYWORDS: sample mean

46. Barbara’s z-score is -1.5. What does this score tell us relative to the mean of the population from which these scores originated?
ANSWER: Her score is 1.5 standard deviations below the mean.
DIFFICULTY: Moderate
REFERENCES: p. 71
Understanding z-Scores
KEYWORDS: z-scores

47. What is the standard deviation of any z-distribution? ANSWER: 1
DIFFICULTY: Easy
REFERENCES: p. 73
Using the z-Distribution to Interpret Scores
KEYWORDS: z-scores

48. Consider the z-scores (in parentheses) for the following individuals: Frank (0.5), Zoe (-1.2), Jimmy (2.9), and Lilly (- 3.3). Which of these individuals would have (a) the lowest score, (b) highest score, (c) and most common score in the distribution?
ANSWER: (a) Lilly’s score is lowest; (b) Jimmy’s score is the highest; and (c) Frank’s score is most common.
DIFFICULTY: Moderate
REFERENCES: p. 74
Using the z-Distribution to Compare Different Variables
KEYWORDS: z-distribution

49. What percentage of scores in a normal distribution fall outside of the range of +3 SDs from the mean?
ANSWER: .0013%+.0013%=.0026%
DIFFICULTY: Moderate
REFERENCES: p. 76
Using the z-Distribution to Compute Relative Frequency
KEYWORDS: z-distribution

50. Suppose a standardized test given to ninth-graders in Texas has a mean score of 125. Suppose at a given school in Texas, the ninth-graders have a mean score of 105. Why is this discrepancy present, and is it problematic?
ANSWER: The discrepancy in scores is not at all necessarily problematic. The sampling distribution of means suggests that different means on a given measure will be found. The central limit theorem suggests that, with a given population, the distribution of scores will be normal.
DIFFICULTY: Moderate
REFERENCES: pp. 79-80
Using z-Scores to Describe Sample Means
KEYWORDS: sampling distribution of means; central limit theorem

51. Suppose you know that a population standard deviation for a given measure is 18. For a sample of 169 subjects who have taken this measure, would would the standard error of the mean be?
ANSWER: 18/13 = 1.38
DIFFICULTY: Moderate
REFERENCES: p. 81
Using z-Scores to Describe Sample Means
KEYWORDS: standard error of the mean

52. Briefly note the three basic procedures used to describe a sample mean from any underlying raw score population.
ANSWER: The three basic steps are to (1) create a sampling distribution of means; (2) Compute the z-score for the sample mean; and (3) use the z-table to determine the relative frequency of the z-score.
DIFFICULTY: Difficult
REFERENCES: p. 84
Using z-Scores to Describe Sample Means

53. Suppose you have a z-score value of 3. You also know the values of the mean of the sampling distribution and the standard error of the mean, both of which are 5. Would would be the sample mean?
ANSWER: 3=(? – 5)/5

sample mean = 20 DIFFICULTY: Difficult REFERENCES: p. 82
Using z-Scores to Describe Sample Means
KEYWORDS: z-score for a sample mean