Chapter 18: Descriptive Statistics

Test Bank

Multiple Choice

1. The purpose of descriptive statistics is to ______.A. make inferences about a population from a sample

B. test hypotheses

C. make interval estimates

D. summarize and explain a set of data

Learning Objective: 18-1: Explain the purpose of descriptive statistics.

Cognitive Domain: Knowledge

Answer Location: Descriptive Statistics

Difficulty Level: Easy

2. A table listing the values of a variable and their frequencies of occurrence is called ______.A. the standard deviation

B. a point estimate

C. a frequency distribution

D. a scatter plot

Learning Objective: 18-3: Explain the difference between a frequency distribution and a grouped frequency distribution.

Cognitive Domain: Application

Answer Location: Frequency Distributions

Difficulty Level: Hard

3. Examine the frequency distribution listed below. The variable is the number of in-service training classes teachers have attended over a 2-year period. What is the mode for the number of in-service classes taken by the teachers?

A. 50

B. 0

C. 3

D. 10

Learning Objective: 18-5: Calculate the mode, median, and mean.

Cognitive Domain: Application

Answer Location: Mode

Difficulty Level: Hard

4. Examine the frequency distribution listed below. The variable is the number of in-service training classes teachers have attended over a 2-year period. This frequency distribution is an example of:

A. descriptive statistics

B. inferential statistics

C. measures of central tendency

D. a contingency table

Learning Objective: 18-2: Distinguish between inferential and descriptive statistics.

Cognitive Domain: Application

Answer Location: Frequency Distributions | Descriptive Statistics

Difficulty Level: Hard

5. In a grouped frequency distribution, it is important that the intervals be ______.A. overlapping

B. no greater than 10 units

C. mutually exclusive

D. no greater than 5 units

Learning Objective: 18-3: Explain the difference between a frequency distribution and a grouped frequency distribution.

Cognitive Domain: Knowledge

Answer Location: Frequency Distributions

Difficulty Level: Easy

6. In a grouped frequency distribution, it is important that the intervals ______.A. are overlapping

B. do not include extreme scores

C. are no greater than 5 units

D. are exhaustive

Learning Objective: 18-3: Explain the difference between a frequency distribution and a grouped frequency distribution.

Cognitive Domain: Knowledge

Answer Location: Frequency Distributions

Difficulty Level: Easy

7. Below are four sets of intervals for grouped frequency distributions. The data that they are based on has scores that range from 0 to 49. Only one set of intervals meets the necessary criteria for groupings. Pick the one that meets the criteria ______.A. 40–49

30–39

20–29

10–19

0–9

B. 40–49

30–39

20–29

10–19

1–9

C. 40–49

30–40

20–30

10–20

0–9

D. 30–40

20–30

10–20

0–10

Learning Objective: 18-3: Explain the difference between a frequency distribution and a grouped frequency distribution.

Cognitive Domain: Application

Answer Location: Frequency Distributions

Difficulty Level: Hard

8. In graphing the frequencies of a single variable (e.g., in a bar graph, histogram, or line graph), the frequencies are put on which axis ______.A. X or abscissa

B. Y or ordinate

Learning Objective: 18-4: Read and interpret bar graphs, line graphs, and scatter plots.

Cognitive Domain: Comprehension

Answer Location: Graphic Representations of Data

Difficulty Level: Medium

9. In graphing the relationship between two variables in a scatter plot, which axes contain the independent and dependent variable?

A. X contains the independent variable and Y contains the dependent variable

B. X contains the dependent variable and Y contains the independent variable

Learning Objective: 18-4: Read and interpret bar graphs, line graphs, and scatter plots.

Cognitive Domain: Application

Answer Location: Graphic Representations of Data

Difficulty Level: Hard

10. The relationship between two quantitative variables is typically represented with a ______.A. line graph

B. scatter plot

C. bar graph

D. frequency distribution

Learning Objective: 18-4: Read and interpret bar graphs, line graphs, and scatter plots.

Cognitive Domain: Comprehension

Answer Location: Scatter Plots (to Visualize a Correlation)

Difficulty Level: Medium

11. Measures of central tendency provide a ______.A. single value that tells you how variable scores are

B. frequency distribution of values

C. single value that tells you about the range of scores

D. single value that is considered most typical of the values of a variable

Learning Objective: 18-6: List the strengths and weaknesses of the mode, median, and mean.

Cognitive Domain: Comprehension

Answer Location: Measures of Central Tendency

Difficulty Level: Medium

12. The median is ______.A. the most frequent score

B. the middle score

C. the highest score

D. the average

Learning Objective: 18-6: List the strengths and weaknesses of the mode, median, and mean.

Cognitive Domain: Comprehension

Answer Location: Median

Difficulty Level: Medium

13. A problem with the mode is that ______.A. its value is affected by extreme scores

B. there might be more than one mode

C. it is always the same as the median

D. calculating its value is complex.

Learning Objective: 18-6: List the strengths and weaknesses of the mode, median, and mean.

Cognitive Domain: Comprehension

Answer Location: A Comparison of the Mean, Median, and Mode

Difficulty Level: Medium

14. What is the median of the following set of scores: 18, 6, 12, 10, 14?

A. 10

B. 14

C. 18

D. 12

Learning Objective: 18-5: Calculate the mode, median, and mean.

Cognitive Domain: Application

Answer Location: Median

Difficulty Level: Hard

15. The mean is ______.A. the score value that divides the distribution in half

B. the average score

C. the most frequent score

D. a measure of variability

Learning Objective: 18-6: List the strengths and weaknesses of the mode, median, and mean.

Cognitive Domain: Comprehension

Answer Location: Mean

Difficulty Level: Medium

16. When is the median the best measure of central tendency?

A. The data are in a symmetrical distribution.

B. When there are a large number of cases.

C. There is a great deal of variability in the scores.

D. The data are highly skewed.

Learning Objective: 18-8: Explain the impact of skewness on the measures of central tendency.

Cognitive Domain: Comprehension

Answer Location: A Comparison of the Mean, Median, and Mode

Difficulty Level: Medium

17. The mode is ______.A. the arithmetic average

B. the middle score

C. the most frequent score

D. a measure of variability

Learning Objective: 18-6: List the strengths and weaknesses of the mode, median, and mean.

Cognitive Domain: Knowledge

Answer Location: Mode

Difficulty Level: Easy

18. What is an advantage of the mean as a measure of central tendency?

A. It is not influenced by extreme scores.

B. It is representative even when there is extreme skewness.

C. It is very stable from sample to sample.

D. It can be used with nominal variables.

Learning Objective: 18-6: List the strengths and weaknesses of the mode, median, and mean.

Cognitive Domain: Comprehension

Answer Location: A Comparison of the Mean, Median, and Mode

Difficulty Level: Medium

19. What is an advantage of the mean as a measure of central tendency?

A. It is not influenced by extreme scores.

B. It is representative even when there is extreme skewness.

C. It is the most precise measure of central tendency.

D. It can be used with nominal variables.

Learning Objective: 18-6: List the strengths and weaknesses of the mode, median, and mean.

Cognitive Domain: Comprehension

Answer Location: A Comparison of the Mean, Median, and Mode

Difficulty Level: Medium

20. What is the disadvantage of the mode as a measure of central tendency?

A. It is influenced by extreme scores.

B. It is imprecise.

C. It cannot be easily interpreted.

D. It does not take into account the magnitude of all the scores.

Learning Objective: 18-6: List the strengths and weaknesses of the mode, median, and mean.

Cognitive Domain: Comprehension

Answer Location: A Comparison of the Mean, Median, and Mode

Difficulty Level: Medium

21. What kind of skew is there in the below distribution?

A. positive skew

B. negative skew

C. symmetrical

D. no skew

Learning Objective: 18-7: Explain positive skew and negative skew.

Cognitive Domain: Application

Answer Location: A Comparison of the Mean, Median, and Mode

Difficulty Level: Hard

22. Which will have the highest score value in the distribution?
 

A. the mode

B. the median

C. the mean

D. the variance

Learning Objective: 18-8: Explain the impact of skewness on the measures of central tendency.

Cognitive Domain: Application

Answer Location: A Comparison of the Mean, Median, and Mode

Difficulty Level: Hard

23. Which will be the best measure of central tendency for these data?
 

A. the mode

B. the median

C. the mean

D. the variance

Learning Objective: 18-8: Explain the impact of skewness on the measures of central tendency.

Cognitive Domain: Application

Answer Location: A Comparison of the Mean, Median, and Mode

Difficulty Level: Hard

24. How is the distribution skewed?

A. positive skew

B. negative skew

C. symmetrical

D. no skew

Learning Objective: 18-7: Explain positive skew and negative skew.

Cognitive Domain: Application

Answer Location: A Comparison of the Mean, Median, and Mode

Difficulty Level: Hard

25. Which will have the highest score value in the distribution?

A. the mode

B. the median

C. the mean

Learning Objective: 18-8: Explain the impact of skewness on the measures of central tendency.

Cognitive Domain: Application

Answer Location: A Comparison of the Mean, Median, and Mode

Difficulty Level: Hard

26. Which will be the best measure of central tendency for these data?

A. the mode

B. the median

C. the mean

Learning Objective: 18-8: Explain the impact of skewness on the measures of central tendency.

Cognitive Domain: Application

Answer Location: A Comparison of the Mean, Median, and Mode

Difficulty Level: Hard

27. Which of the following distributions is closest to being symmetrical?

A.

B.

C.

Learning Objective: 18-7: Explain positive skew and negative skew.

Cognitive Domain: Application

Answer Location: A Comparison of the Mean, Median, and Mode

Difficulty Level: Hard

28. Which of the following distributions is negatively skewed?

A.

B.

C.

Learning Objective: 18-7: Explain positive skew and negative skew.

Cognitive Domain: Application

Answer Location: A Comparison of the Mean, Median, and Mode

Difficulty Level: Hard

29. Which of the following distributions is positively skewed?

A.

B.

C.

Learning Objective: 18-7: Explain positive skew and negative skew.

Cognitive Domain: Application

Answer Location: A Comparison of the Mean, Median, and Mode

Difficulty Level: Hard

30. Which of the data points in the following distribution seems to be an outlier: 8, 10, 12, 14, 12, 15, 2,000?

A. 8

B. 10

C. 14

D. 2,000

Learning Objective: 18-7: Explain positive skew and negative skew.

Cognitive Domain: Application

Answer Location: A Comparison of the Mean, Median, and Mode

Difficulty Level: Hard

31. Measures of variability indicate ______.A. where the modal score lies

B. the median score value

C. the degree of skewness in the distribution

D. how spread out scores are in a distribution

Learning Objective: 18-9: Describe and interpret the different measures of variability.

Cognitive Domain: Comprehension

Answer Location: Measures of Variability

Difficulty Level: Medium

32. The range refers to ______.A. the difference between the lowest and highest score

B. the difference between the mean and the median

C. the mode in a bimodal distribution

D. the difference between a score and the mean

Learning Objective: 18-9: Describe and interpret the different measures of variability.

Cognitive Domain: Knowledge

Answer Location: Range

Difficulty Level: Easy

33. What is the range of the following set of data: 10, 20, 40, 50, 70, 100, 110?

A. 90

B. 80

C. 10

D. 100

Learning Objective: 18-10: Calculate the range, variance, and standard deviation.

Cognitive Domain: Application

Answer Location: Range

Difficulty Level: Hard

34. What is the variance?

A. the difference between the lowest and highest score

B. the difference between a score and the mean

C. the average squared distance from the mean

D. a measure of central tendency

Learning Objective: 18-9: Describe and interpret the different measures of variability.

Cognitive Domain: Comprehension

Answer Location: Variance and Standard Deviation

Difficulty Level: Medium

35. The standard deviation is ______.A. the square root of the variance

B. a measure of central tendency

C. a theoretical construct

D. an inferential statistic

Learning Objective: 18-9: Describe and interpret the different measures of variability.

Cognitive Domain: Knowledge

Answer Location: Variance and Standard Deviation

Difficulty Level: Easy

36. If your grade on a test was determined by your standing relative to others in a class and you had a score of 90, what class should you most like to be in (hint: which one has the largest z score)?

A. mean grade = 85, SD = 10

B. mean grade = 83, SD = 5

C. mean grade = 80, SD = 20

D. mean grade = 90, SD = 5

Learning Objective: 18-11: Explain percentile ranks and z scores.

Cognitive Domain: Application

Answer Location: z Scores

Difficulty Level: Hard

37. Approximately what percentage of scores falls within one standard deviation of the mean in a normal distribution?

A. 34%

B. 95%

C. 99%

D. 68%

Learning Objective: 18-9: Describe and interpret the different measures of variability.

Cognitive Domain: Knowledge

Answer Location: Standard Deviation and the Normal Distribution

Difficulty Level: Easy

38. Approximately what percentage of scores falls within two standard deviations of the mean in a normal distribution?

A. 34%

B. 95%

C. 99%

D. 68%

Learning Objective: 18-9: Describe and interpret the different measures of variability.

Cognitive Domain: Knowledge

Answer Location: Standard Deviation and the Normal Distribution

Difficulty Level: Easy

39. A percentile rank tells you ______.A. the percent correct on a test

B. the percent of people who scored better than you

C. the percent of people in a particular group who score below your score value

D. how far above or below the mean you are in percentages

Learning Objective: 18-11: Explain percentile ranks and z scores.

Cognitive Domain: Comprehension

Answer Location: Percentile Ranks

Difficulty Level: Medium

40. Joe had a percentile rank of 70 on a standardized math test. What does that mean?

A. He did poorly, since he only correctly answered 70% of the questions.

B. He did well in that he scored higher than 70% of the people that took the test.

C. He did well, in that he answered 70% of the items correctly.

D. He did poorly since he only answered 70% of the items that an average individual would answer correctly.

Learning Objective: 18-11: Explain percentile ranks and z scores.

Cognitive Domain: Analysis

Answer Location: Percentile Ranks

Difficulty Level: Medium

41. A z score transforms a raw score into ______.A. percent correct

B. a ratio of right to wrong answers

C. a range

D. standard deviation units

Learning Objective: 18-11: Explain percentile ranks and z scores.

Cognitive Domain: Knowledge

Answer Location: z Scores

Difficulty Level: Easy

42. The plus or minus sign before a z score tells you ______.A. whether a score is above or below the mean

B. the magnitude of the score

C. the correlation

D. the variability

Learning Objective: 18-11: Explain percentile ranks and z scores.

Cognitive Domain: Comprehension

Answer Location: z Scores

Difficulty Level: Medium

43. The denominator (bottom) of the z score formula is ______.A. the standard deviation

B. the difference between a score and the mean

C. the range

D. the mean

Learning Objective: 18-11: Explain percentile ranks and z scores.

Cognitive Domain: Knowledge

Answer Location: z Scores

Difficulty Level: Medium

44. The numerator of the z score formula is ______.A. the standard deviation

B. the difference between a score and the mean

C. the range

D. the mean

Learning Objective: 18-11: Explain percentile ranks and z scores.

Cognitive Domain: Knowledge

Answer Location: z Scores

Difficulty Level: Medium

45. A z score of 0.00 means that ______.A. a person had zero points on a test

B. a person scored at the mean

C. a person scored below the mean

D. a person scored in the bottom percentile

Learning Objective: 18-11: Explain percentile ranks and z scores.

Cognitive Domain: Application

Answer Location: z Scores

Difficulty Level: Hard

46. In a normal distribution, 95% of the scores fall between z scores of ______.

A. –1 thru +1

B. –2 thru +2

C. –3 thru +3

D. 0 thru + 3

Learning Objective: 18-11: Explain percentile ranks and z scores.

Cognitive Domain: Application

Answer Location: z Scores

Difficulty Level: Hard

47. On an IQ test with a mean of 100 and a standard deviation of 15, what is the z score for someone with an IQ of 70?

A. –1.30

B. –2.00

C. –1.00

D. –13

Learning Objective: 18-11: Explain percentile ranks and z scores.

Cognitive Domain: Analysis

Answer Location: z Scores

Difficulty Level: Medium

48. Below are z scores for four people who took a test. Which one scored the highest?
John –2.9, Samantha +2.1, Sally +0.1, and Joshua +1.0

A. John

B. Samantha

C. Sally

D. Joshua

Learning Objective: 18-11: Explain percentile ranks and z scores.

Cognitive Domain: Analysis

Answer Location: z Scores

Difficulty Level: Medium

49. A contingency table is ______.A. a frequency distribution for a single variable

B. a table displaying information in cells formed by the intersection of two or more categorical variables

C. a table containing correlation coefficients

D. a normal curve representation of two variables

Learning Objective: 18-12: Explain how to construct and interpret a contingency table.

Cognitive Domain: Knowledge

Answer Location: Contingency Tables

Difficulty Level: Easy

50. Below is a contingency table containing frequencies and column percentages that looks at the relationship between handedness and majoring in science versus the humanities. Is there a likely relationship between handedness and major?

A. Yes

B. No

Learning Objective: 18-12: Explain how to construct and interpret a contingency table.

Cognitive Domain: Application

Answer Location: Contingency Tables

Difficulty Level: Hard

51. Based on the information in the table, which statement best captures the relationship between handedness and major ?

A. Major is unrelated to handedness.

B. Left-handed people are more likely to major in humanities than right-handed people.

C. Right-handed people are more likely to major in science than left-handed people.

D. Left-handed people are more likely to major in science than right-handed people.

Learning Objective: 18-12: Explain how to construct and interpret a contingency table.

Cognitive Domain: Application

Answer Location: Contingency Tables

Difficulty Level: Hard

52. Examine the following table. A researcher is interested in whether learning from instruction that includes video will be more likely to transfer (be applicable in new contexts) than learning that takes place with still photos or a written document. Is there a likely relationship between instructional group and transfer of learning? Note that the percentages in parentheses are those within the columns.

A. Yes

B. No

Learning Objective: 18-12: Explain how to construct and interpret a contingency table.

Cognitive Domain: Application

Answer Location: Contingency Tables

Difficulty Level: Hard

53. Which statement below is true?

A. Instructional group is unrelated to transfer of learning.

B. The video group was 3 times more likely to transfer than the text group.

C. The video group was less likely to transfer than the picture group.

D. The text group was more likely to transfer than the picture group.

Learning Objective: 18-12: Explain how to construct and interpret a contingency table.

Cognitive Domain: Application

Answer Location: Contingency Tables

Difficulty Level: Hard

54. Examine the following table (percentages are within each column). A researcher is interested in whether learning from instruction that includes video will be more likely to transfer (be applicable in new contexts) than learning that takes place with still photos or a written document. Which statement below is true?

A. The video group was less likely to transfer than the picture group.

B. The picture group had the largest number of participants show transfer.

C. The picture group was more likely to transfer than the written text group.

D. All groups were equally likely to show transfer of learning.

Learning Objective: 18-12: Explain how to construct and interpret a contingency table.

Cognitive Domain: Application

Answer Location: Contingency Tables

Difficulty Level: Hard

55. Regression analysis involves ______.A. creating a graph that shows changes across time

B. creating a test where people do not regress toward the mean

C. a statistical procedure used to predict or explain the values of a dependent variable based on the values of one or more independent variables

D. a statistical procedure for analyzing contingency table

Learning Objective: 18-13: Explain the difference between simple and multiple regression.

Cognitive Domain: Knowledge

Answer Location: Regression Analysis

Difficulty Level: Easy

56. A simple regression examines ______.A. how two or more independent variables predict or explain the scores on a dependent variable

B. how to create a graph that shows changes across time

C. how one independent variable is confounded with another independent variable

D. the prediction or explanation of scores on one dependent variable based on the scores from one independent variable

Learning Objective: 18-13: Explain the difference between simple and multiple regression.

Cognitive Domain: Knowledge

Answer Location: Regression Analysis

Difficulty Level: Easy

57. Multiple regression examines ______.A. how two or more independent variables predict or explain the scores on a single dependent variable

B. how to create a graph that shows changes across time

C. how one independent variable is confounded with another independent variable

D. the prediction of one dependent variable from one independent variable

Learning Objective: 18-13: Explain the difference between simple and multiple regression.

Cognitive Domain: Knowledge

Answer Location: Regression Analysis

Difficulty Level: Easy

58. In a regression equation, the y-intercept defines ______.A. the point where the regression line crosses the y-axis

B. the point where the regression line crosses the x-axis

C. the amount of change in the dependent variable per one unit change in the independent variable

D. the amount of change in the independent variable per one unit change in the dependent variable

Learning Objective: 18-14: Explain the difference between the y-intercept and the regression coefficient.

Cognitive Domain: Knowledge

Answer Location: Simple Regression

Difficulty Level: Easy

59. In a simple regression, the regression coefficient tells you ______.A. the mean of the variable

B. the point where the regression line crosses the x-axis

C. the amount of change in the dependent variable per unit change in the independent variable

D. the amount of change in the independent variable per one unit change in the dependent variable

Learning Objective: 18-14: Explain the difference between the y-intercept and the regression coefficient.

Cognitive Domain: Knowledge

Answer Location: Simple Regression

Difficulty Level: Easy

60. Below is a regression equation predicting children’s math achievement from their parents’ education level (years of education).

Y = 1 + 2x,

where x is the number of years of parental education.

What would be the predicted score for a child whose parents had 12 years of education?

A. 15

B. 24

C. 25

D. 3

Learning Objective: 18-14: Explain the difference between the y-intercept and the regression coefficient.

Cognitive Domain: Application

Answer Location: Simple Regression

Difficulty Level: Hard

61. Let us suppose we are predicting the score on a training posttest from the number of years of education and the score on an aptitude test given before training. Here is the regression equation:

Y = 25 + .5X₁ +10X₂,

where X₁ = years of education and X₂ = aptitude test score.

What is the predicted score for someone with 10 years of education and an aptitude test score of 5?

A. 25

B. 50

C. 35

D. 80

Learning Objective: 18-14: Explain the difference between the y-intercept and the regression coefficient.

Cognitive Domain: Analysis

Answer Location: Multiple Regression

Difficulty Level: Hard

62. Let us suppose we are predicting the score on a training posttest from the number of years of education and the score on an aptitude test given before training. Here is the regression equation:

Y = 25 + .5X₁ +10X₂,

where X₁ = years of education and X₂ = aptitude test score.

What does the .5 in front of X₁ tell us?

A. where the equation crosses the y-axis

B. how much change in posttest score you get per unit change in aptitude test score

C. how much change in the posttest score you get per unit change in years of education

D. how much change in the years of education you get per unit change in posttest score

Learning Objective: 18-14: Explain the difference between the y-intercept and the regression coefficient.

Cognitive Domain: Analysis

Answer Location: Multiple Regression

Difficulty Level: Medium

63. Let us suppose we are predicting the score on a training posttest from the number of years of education and the score on an aptitude test given before training. Here is the regression equation:

Y = 25 + .5X₁ +10X₂,

where X₁ = years of education and X₂ = aptitude test score.

Which of the following are true about this equation?

A. The equation is a simple regression analysis.

B. The regression coefficient for aptitude test controls for years of education.

C. The equation is in standard score form.

D. For every unit change in X₁, there is a 10 unit change in Y.

Learning Objective: 18-13: Explain the difference between simple and multiple regression.

Cognitive Domain: Analysis

Answer Location: Multiple Regression

Difficulty Level: Medium

64. In simple regression, the ______ is defined as the predicted change in Y given a one-unit change in X.

A. y intercept

B. regression coefficient

C. error term

D. x intercept

Learning Objective: 18-13: Explain the difference between simple and multiple regression.

Cognitive Domain: Knowledge

Answer Location: Simple Regression

Difficulty Level: Easy

65. When the points in a scatter plot clearly move in a bottom-left to top-right direction, one has a ______ relationship.

A. positive

B. negative

C. causative

D. none of these

Learning Objective: 18-4: Read and interpret bar graphs, line graphs, and scatter plots.

Cognitive Domain: Analysis

Answer Location: Scatter Plots (to Visualize a Correlation)

Difficulty Level: Medium

66. When the points in a scatter plot clearly move in a top-left to bottom-right direction, one has a ______ relationship.

A. positive

B. negative

C. causative

D. none of these

Learning Objective: 18-4: Read and interpret bar graphs, line graphs, and scatter plots.

Cognitive Domain: Analysis

Answer Location: Scatter Plots (to Visualize a Correlation)

Difficulty Level: Medium

67. If you sum your scores for a variable and divide that sum by the number of scores in the variable, what do you obtain?

A. mode

B. median

C. mean

D. variance

Learning Objective: 18-5: Calculate the mode, median, and mean.

Cognitive Domain: Application

Answer Location: Mean

Difficulty Level: Hard

68. If you square the standard deviation, what do you obtain?

A. range

B. variance

C. percentile rank

D. median

Learning Objective: 18-10: Calculate the range, variance, and standard deviation.

Cognitive Domain: Knowledge

Answer Location: Variance and Standard Deviation

Difficulty Level: Easy

69. If the owner of Microsoft moved into your neighborhood, which of the following statistical indexes for the income in your neighborhood would become radically larger?

A. mean

B. median

C. mode

D. percentile rank

Learning Objective: 18-6: List the strengths and weaknesses of the mode, median, and mean.

Cognitive Domain: Application

Answer Location: Mean

Difficulty Level: Hard

70. An IQ score of 100 is equivalent to a z score of ______.

A. 15

B. 1

C. 0

D. –1

Learning Objective: 18-11: Explain percentile ranks and z scores.

Cognitive Domain: Application

Answer Location: z Scores

Difficulty Level: Hard

71. If you want to determine the relationship between two or more categorical variables, what should you do?

A. calculate the Pearson Product Moment Correlation Coefficient

B. construct a contingency table

C. conduct a regression analysis

D. conduct an analysis of variance

Learning Objective: 18-12: Explain how to construct and interpret a contingency table.

Cognitive Domain: Comprehension

Answer Location: Contingency Tables

Difficulty Level: Medium

72. Below is a regression equation predicting children’s math achievement from their parents’ education level (years of education). Y = 1 + 2x,

where x is the number of years of parental education.

What would be the predicted score for a child whose parents had 10 years of education?

A. 21

B. 20

C. 12

D. 11

Learning Objective: 18-13: Explain the difference between simple and multiple regression.

Cognitive Domain: Application

Answer Location: Simple Regression

Difficulty Level: Hard

73. Sally wants to graphically represent her data from her study. She collected data on the number of hours her students spent on homework every day of the week. What pictorial representation should she use for her study?

A. a bar graph

B. a histogram

C. a contingency table

D. a scatter plot

Learning Objective: 18-4: Read and interpret bar graphs, line graphs, and scatter plots.

Cognitive Domain: Application

Answer Location: Histograms

Difficulty Level: Hard

74. While studying families living in an inner city neighborhood (where most of the residents have incomes well below the poverty level), Dr. Westbrook found that one resident was actually a very wealthy individual. In terms of income level this person would be considered a(n) ______.

A. variance

B. standard deviation

C. outlier

D. mode

Learning Objective: 18-6: List the strengths and weaknesses of the mode, median, and mean.

Cognitive Domain: Application

Answer Location: A Comparison of the Mean, Median, and Mode

Difficulty Level: Hard

75. A measure of variability is a numerical index ______.A. of the central tendency of the data values in a set of data

B. that indicates how spread out the data values are in a set of data

C. that indicates the level of skewness of the data

D. that indicates if two variables vary together

Learning Objective: 18-9: Describe and interpret the different measures of variability.

Cognitive Domain: Comprehension

Answer Location: Measures of Variability

Difficulty Level: Medium

76. A researcher gathered the following set of data: 54, 56, 56, 56, 57, 57, 58, 58, 59, 59. Which term would best describe these data?

A. homogeneous

B. heterogeneous

C. skewed

D. homoscedastic

Learning Objective: 18-9: Describe and interpret the different measures of variability.

Cognitive Domain: Application

Answer Location: Measures of Variability

Difficulty Level: Hard

77. A researcher is planning a study that has one dependent variable and two independent variables. Which data analysis procedure would she use?

A. simple regression analysis

B. standard deviation analysis

C. multiple regression analysis

D. z score analysis

Learning Objective: 18-13: Explain the difference between simple and multiple regression.

Cognitive Domain: Comprehension

Answer Location: Multiple Regression

Difficulty Level: Medium

78. Joe wants to make assumptions about characteristics of a population based upon his sample. In order to do this he must use ______.

A. descriptive statistics

B. inferential statistics

C. multiple regression

D. point estimates

Learning Objective: 18-1: Explain the purpose of descriptive statistics.

Cognitive Domain: Application

Answer Location: Descriptive Statistics

Difficulty Level: Hard

79. If you wanted to characterize, summarize, and/or explain data you had collected you would use ______.A. descriptive statistics

B. inferential statistics

C. multiple regression

D. hypothesis testing

Learning Objective: 18-1: Explain the purpose of descriptive statistics.

Cognitive Domain: Application

Answer Location: Descriptive Statistics

Difficulty Level: Hard

80. Helen has used vertical bars to represent her categorical data. She has created a ______.A. frequency distribution

B. histogram

C. scatterplot

D. bar graph

Learning Objective: 18-4: Read and interpret bar graphs, line graphs, and scatter plots.

Cognitive Domain: Application

Answer Location: Bar Graphs

Difficulty Level: Hard

81. Helen is doing a study where she is looking at the percentage of students proficient in mathematics over a 10-year period in a school district. What would be the best way to display the trend in percentages?

A. a scatterplot

B. a bar graph

C. a line graph

D. calculate the mean and standard deviation

Learning Objective: 18-4: Read and interpret bar graphs, line graphs, and scatter plots.

Cognitive Domain: Application

Answer Location: Line Graphs

Difficulty Level: Hard

82. With normally distributed IQ scores with a mean of 100 and a standard deviation of 15, what is the range of scores between which 95% of people should score?

A. 100 and 130

B. 85 and 115

C. 70 and 100

D. 70 and 130

Learning Objective: 18-9: Describe and interpret the different measures of variability.

Cognitive Domain: Application

Answer Location: Standard Deviation and the Normal Distribution

Difficulty Level: Hard

83. Scores that have been converted from one scale to another so that they have a particular mean and standard deviation are called ______.A. percentile ranks

B. deviation scores

C. change scores

D. standard scores

Learning Objective: 18-11: Explain percentile ranks and z scores.

Cognitive Domain: Knowledge

Answer Location: Measures of Relative Standing

Difficulty Level: Easy

84. The regression line is ______.A. the line that splits the distribution in half

B. the line that best fits a pattern of observations

C. a line between the median and the mean

D. a line between the median and the mode

Learning Objective: 18-13: Explain the difference between simple and multiple regression.

Cognitive Domain: Comprehension

Answer Location: Simple Regression

Difficulty Level: Medium

85. Harold needs to calculate a median. The scores he has are: 10, 1, 9, 3, 4, 8, 6, 5, 2, and 7. The median is ______.

A. 4.5

B. 5

C. 5.5

D. 6

Learning Objective: 18-5: Calculate the mode, median, and mean.

Cognitive Domain: Application

Answer Location: Median

Difficulty Level: Hard

86. On his statistics test, Tom has to calculate a mean on the following scores: 5, 5, 10, 15, and 15. What answer should he come up with?

A. 5

B. 9

C. 10

D. 15

Learning Objective: 18-5: Calculate the mode, median, and mean.

Cognitive Domain: Application

Answer Location: Mean

Difficulty Level: Hard

87. Claudia calculated the variance for her data. The value she came up with was 81. What is the standard deviation for her data?

A. 3

B. 9

C. 10

D. 81

Learning Objective: 18-10: Calculate the range, variance, and standard deviation.

Cognitive Domain: Application

Answer Location: Variance and Standard Deviation

Difficulty Level: Hard

88. Charlie was looking at the variability of his data. The range for his sample was 150. The variance for his sample was 49. What is the standard deviation for the sample?

A. 7

B. 9

C. 4.9

D. There is not enough information to tell.

Learning Objective: 18-10: Calculate the range, variance, and standard deviation.

Cognitive Domain: Application

Answer Location: Variance and Standard Deviation

Difficulty Level: Hard

89. In regression, the slope of the regression line is indicated by the ______.

A. range

B. y intercept

C. regression coefficient

D. partial regression coefficient

Learning Objective: 18-14: Explain the difference between the y-intercept and the regression coefficient.

Cognitive Domain: Knowledge

Answer Location: Simple Regression

Difficulty Level: Easy

True/False

1. The purpose of descriptive statistics is to go beyond the immediate data and draw conclusions about the characteristics of populations

Learning Objective: 18-1: Explain the purpose of descriptive statistics.

Cognitive Domain: Knowledge

Answer Location: Descriptive Statistics

2. A histogram is a graphic that shows the frequencies and shape that characterize a quantitative variable.

Learning Objective: 18-4: Read and interpret bar graphs, line graphs, and scatter plots.

Cognitive Domain: Knowledge

Answer Location: Histograms

Difficulty Level: Easy

3. If the owner of Microsoft moved into your neighborhood, the distribution of incomes in your neighborhood would become highly skewed to the right.

Learning Objective: 18-7: Explain positive skew and negative skew.

Cognitive Domain: Comprehension

Answer Location: A Comparison of the Mean, Median, and Mode

Difficulty Level: Medium

4. When a distribution of data is perfectly symmetrical, the mean, median, and mode will have the same value.

Learning Objective: 18-8: Explain the impact of skewness on the measures of central tendency.

Cognitive Domain: Knowledge

Answer Location: A Comparison of the Mean, Median, and Mode

Difficulty Level: Easy

5. If the mean is less than the median, the data are probably skewed to the right.

Learning Objective: 18-8: Explain the impact of skewness on the measures of central tendency.

Cognitive Domain: Comprehension

Answer Location: A Comparison of the Mean, Median, and Mode

Difficulty Level: Medium

6. If everyone in your neighborhood had exactly the same income, the variance would be equal to zero.

Learning Objective: 18-9: Describe and interpret the different measures of variability.

Cognitive Domain: Application

Answer Location: Variance and Standard Deviation

Difficulty Level: Medium

7. You take the ACT and have a percentile rank of 84. Your percentile rank shows your standing relative to a reference or norming group.

Learning Objective: 18-11: Explain percentile ranks and z scores.

Cognitive Domain: Comprehension

Answer Location: Percentile Ranks

Difficulty Level: Medium

8. A partial regression coefficient shows the relationship between one IV in the multiple regression equation and the DV, controlling for the other IVs in the regression equation.

Learning Objective: 18-13: Explain the difference between simple and multiple regression.

Cognitive Domain: Comprehension

Answer Location: Multiple Regression

Difficulty Level: Medium

9. When data are more heterogeneous, the standard deviation will tend to be larger.

Learning Objective: 18-9: Describe and interpret the different measures of variability.

Cognitive Domain: Comprehension

Answer Location: Variance and Standard Deviation

Difficulty Level: Medium

10. When the data tend to be homogeneous, the variance and standard deviation will tend to be larger.

Learning Objective: 18-9: Describe and interpret the different measures of variability.

Cognitive Domain: Comprehension

Answer Location: Variance and Standard Deviation

Difficulty Level: Medium

11. A multiple regression equation based on one dependent variable and four independent variables will have two partial regression coefficients.

Learning Objective: 18-13: Explain the difference between simple and multiple regression.

Cognitive Domain: Application

Answer Location: Simple Regression | Multiple Regression

Difficulty Level: Medium

12. The variance is the average distance of the scores from the mean, in squared units.

Learning Objective: 18-10: Calculate the range, variance, and standard deviation.

Cognitive Domain: Comprehension

Answer Location: Variance and Standard Deviation

Difficulty Level: Medium

13. A measure of central tendency provides information about the variability within a distribution.

Learning Objective: 18-5: Calculate the mode, median, and mean.

Cognitive Domain: Comprehension

Answer Location: Measures of Central Tendency

Difficulty Level: Medium

14. Percentile ranks and z scores describe where a score falls in relation to other scores in the distribution of data.

Learning Objective: 18-11: Explain percentile ranks and z scores.

Cognitive Domain: Comprehension

Answer Location: Measures of Relative Standing

Difficulty Level: Medium

15. To calculate a variance, you take the square root of the standard deviation.

Learning Objective: 18-10: Calculate the range, variance, and standard deviation.

Cognitive Domain: Comprehension

Answer Location: Variance and Standard Deviation

Difficulty Level: Medium

Essay

1. Compare and contrast descriptive and inferential statistics.

Learning Objective: 18-2: Distinguish between inferential and descriptive statistics.

Cognitive Domain: Analysis

Answer Location: Descriptive Statistics

Difficulty Level: Medium

2. Describe the similarities of and differences between frequency distributions and grouped frequency distributions.

Learning Objective: 18-3: Explain the difference between a frequency distribution and a grouped frequency distribution.

Cognitive Domain: Analysis

Answer Location: Frequency Distributions

Difficulty Level: Medium

3. Explain what we mean by positive and negative skew.

Learning Objective: 18-7: Explain positive skew and negative skew.

Cognitive Domain: Analysis

Answer Location: A Comparison of the Mean, Median, and Mode

Difficulty Level: Medium

4. Compare and contrast simple and multiple regression.

Learning Objective: 18-13: Explain the difference between simple and multiple regression.

Cognitive Domain: Analysis

Answer Location: Simple Regression | Multiple Regression

Difficulty Level: Medium

5. How do the y-intercept and the regression coefficient differ?

Learning Objective: 18-14: Explain the difference between the y-intercept and the regression coefficient.

Cognitive Domain: Knowledge

Answer Location: Simple Regression

Difficulty Level: Easy