Deck 17: Statistical Methods

Question 1

The marketing agent for a professional sports franchise conducts a survey asking people how much they support the construction of a new sports stadium.Almost everyone who takes part in the survey indicates they are strongly in favor of a new stadium; there are just a few respondents who think a new stadium would be a bad idea.When the results from the survey are plotted in a histogram,the distribution will be

A) positively skewed.
B) symmetrical.
C) impossible to predict without more information.
D) negatively skewed.

Answer 1

negatively skewed.

Question 2

Professor Latimore gives an exam that turns out to be exceptionally easy and everyone does well,yielding a

A) normal distribution.
B) negatively skewed distribution.
C) positively skewed distribution.
D) bimodal distribution.

Answer 2

negatively skewed distribution.

Question 3

Your psychology professor wants to organize and summarize the scores on the first psychology test; which type of statistics is your professor MOST likely to use?

A) descriptive statistics
B) inferential statistics
C) correlational statistics
D) significant statistics

Answer 3

descriptive statistics

Question 4

The use of mathematics to organize,summarize and interpret numerical data is known as

A) statistical significance.
B) standard deviation.
C) statistics.
D) variability.

Question 5

A table that uses an organized arrangement to indicate how frequently each score or group of scores occurs in a set of data is a

A) frequency polygon.
B) histogram.
C) frequency distribution.
D) frequency table.

Question 6

Toshi has collected data for her research.She wants to create an orderly arrangement of scores that would indicate the frequency of each score; she would be MOST likely to use a

A) scatterplot.
B) frequency distribution.
C) histogram.
D) frequency polygon.

Question 7

Scores pile up at the low end of the scale in

A) a negatively skewed distribution.
B) a positively skewed distribution.
C) any skewed distribution.
D) a normal distribution.

Question 8

The three measures of central tendency tend to converge in a

A) symmetrical distribution.
B) asymmetrical distribution.
C) positively skewed distribution.
D) negatively skewed distribution.

Question 9

Researchers use statistics to do all of the following EXCEPT

A) to interpret numerical data.
B) to collect numerical data.
C) to summarize numerical data.
D) to organize numerical data.

Question 10

A histogram is a

A) graph that represents a symmetrical or bell-shaped curve.
B) bar graph that presents data from a frequency distribution.
C) line figure that presents data from a frequency distribution.
D) graph in which paired scores for each subject are plotted as single points.

Question 11

Dr.Trane wants to create a line figure to present her data that would indicate the frequency of each score.Dr.Trane will be MOST likely to use a

A) scatterplot.
B) frequency distribution.
C) histogram.
D) frequency polygon.

Question 12

A frequency polygon is a

A) graph that represents a symmetrical or bell-shaped curve.
B) bar graph that presents data from a frequency distribution.
C) line figure that presents data from a frequency distribution.
D) graph in which paired scores for each subject are plotted as single points.

Question 13

Before you construct a histogram you need to

A) calculate an inferential statistic.
B) calculate a correlation.
C) create a frequency distribution.
D) create a series of percentile ranks.

Question 14

Stefan has collected a large amount of data in a study designed to test the effectiveness of a new drug meant to slow the progression of Alzheimer's disease.To organize and summarize his data,which type of statistics would he use?

A) descriptive statistics
B) correlational statistics
C) normal statistics
D) inferential statistics

Question 15

In both bar graphs and frequency polygons,the horizontal axis is typically used to indicate

A) all the possible scores in a data set.
B) the frequency of each score in a data set.
C) the average scores for the entire data set.
D) the strength of the correlation among the scores in a data set.

Question 16

Which measure of central tendency is obtained by adding all the scores and dividing that total by the number of scores?

A) mode
B) median
C) mean
D) range

Question 17

Techniques to graphically represent the frequency of scores in a set of data include

A) histograms and frequency polygons.
B) frequency distributions and frequency polygons.
C) frequency distributions and scatter diagrams.
D) histograms and scatter diagrams.

Question 18

Dr.Kleiman gives an exam where most of the students receive failing grades and only a few students receive high scores.When the exam scores are plotted,the distribution will be

A) positively skewed.
B) negatively skewed.
C) symmetrical.
D) impossible to predict without more information.

Question 19

The use of statistics to organize and summarize data BEST describes the purpose of

A) normal statistics
B) correlational statistics
C) inferential statistics
D) descriptive statistics

Question 20

Histograms and frequency polygons typically list possible scores on the ____ and indicate frequency of the scores on the ____.

A) horizontal axis; vertical axis
B) vertical axis; horizontal axis
C) left side; right side
D) right side; left side

Question 21

The standard deviation

A) indicates the average difference between each score in a group and the mean for that group of scores.
B) reveals the degree of skew for a group of scores.
C) is sensitive to scores at the extremes of a distribution of scores.
D) is used to determine whether a data set is positively or negatively skewed.

Question 22

What is the mode of the following set of scores: 1,2,5,6,6?

A) 2
B) 4
C) 5
D) 6

Question 23

The index of the amount of variability in a set of data is known as the

A) mean.
B) standard deviation.
C) median.
D) frequency distribution.

Question 24

A professor who has two sections of the same course gives an exam.Both classes have the same mean score on the exam.However,in Class A most students scored relatively close to the mean,while in Class B many students scored either much higher or much lower than the mean.Which statement best describes the distribution of grades for the two classes?

A) the standard deviation will be the same for the two classes
B) the standard deviation will be larger for Class A than for Class B
C) the standard deviation will be smaller for Class A than for Class B
D) not enough information is provided to draw any conclusion regarding the standard deviation

Question 25

The median is determined by

A) arranging the scores in increasing order and finding the middle score.
B) finding the most frequently occurring score.
C) adding up all the scores and dividing by the number of scores.
D) dividing the middle score by the number of scores.

Question 26

In the formula for the standard deviation,the symbol S stands for

A) summation.
B) sum of the squares.
C) deviation from the mean.
D) deviation from the normal distribution.

Question 27

When the distribution of scores is symmetrical

A) the mean, median, and mode are relatively far apart in value.
B) the mean, median, and mode are relatively close together in value.
C) only the median and mode are relatively close together in value.
D) only the mean and mode are relatively close together in value.

Question 28

In a strongly skewed distribution,the best indicator of central tendency is usually the

A) mean.
B) median.
C) mode.
D) standard deviation.

Question 29

If you add all the scores in a group of scores together and divide by the number of scores,the result is the

A) variability.
B) median.
C) mean.
D) mode.

Question 30

When a distribution of scores is not symmetrical and many scores pile up at the low end of the scale,the distribution is a

A) positively skewed distribution.
B) negatively skewed distribution.
C) significant distribution.
D) normal distribution.

Question 31

The square root of Sd²/n is the formula for the

A) central tendency.
B) standard deviation.
C) frequency distribution.
D) correlation coefficient.

Question 32

The statistical concept of ____ refers to how much the scores in a distribution of scores tend to vary or depart from the mean.

A) correlation
B) variability
C) central tendency
D) dispersion

Question 33

An index of the amount of variability that exists in a distribution of scores is the

A) central tendency.
B) standard deviation.
C) frequency distribution.
D) correlation coefficient.

Question 34

Which of the following statements BEST describes a skewed distribution?

A) the distribution is symmetrical or balanced
B) the distribution is not symmetrical or balanced
C) many scores in the distribution are high
D) many scores in the distribution are low

Question 35

Aster knows that the distribution of incomes for university students has a strong positive skew.In this case the best index of central tendency for Aster to use would be the

A) median.
B) mode.
C) mean.
D) standard deviation.

Question 36

When a frequency polygon has a sharp peak near the center,and very few scores away from the center,you would expect that

A) the mode for the data set will be greater than the mean.
B) the standard deviation for the data set will be high.
C) the standard deviation for the data set will be low.
D) the mean for the data set will be less than the median.

Question 37

When scores are "bunched up" in the center of a distribution,the

A) mean will be relatively low.
B) standard deviation will be relatively low.
C) correlation coefficient will be a negative number.
D) standard deviation will be relatively high.

Question 38

The formula for the standard deviation is

A) d²/n.
B) S X/n.
C) square root of Sd²/n.
D) square root of S X/n.

Question 39

When a distribution of scores includes a few extreme scores (either extremely high or extremely low)the ____ usually provides the best index of central tendency.

A) average
B) median
C) mean
D) mode

Question 40

Al and Carmen have the same bowling average,but Al is much more erratic than Carmen.If we compute the standard deviations for their respective distributions of bowling scores,which of the following will be true?

A) Al's standard deviation will be higher than Carmen's.
B) Marilyn's standard deviation will be higher than Al's.
C) Both standard deviations will be the same.
D) Al's scores will be symmetrical while Carmen's will be positively skewed.

Question 41

A positive correlation is to a direct relationship as a negative correlation is to

A) an ascending relationship.
B) a descending relationship.
C) an inverse relationship.
D) an inferential relationship.

Question 42

When scores from a personality scale designed to measure agreeableness are plotted,the scores follow a normal distribution.This means that

A) the scores are evenly distributed across the entire range of possible scores.
B) people who score high in agreeableness tend to score high in other personality traits.
C) people who score high in agreeableness tend to score low in other personality traits.
D) most people score near the middle of the scale, and there are fewer people who score extremely high or extremely low in agreeableness.

Question 43

When a trait has a normal distribution,the unit of measurement used to assess where any score falls in the distribution is the

A) variability.
B) standard deviation.
C) mean.
D) correlation coefficient.

Question 44

Scores on standardized intelligence tests are normally distributed with a mean of 100 and a standard deviation of 15.This means that

A) 50% of the population scores between 70 and 100 on standardized intelligence tests.
B) only 5% of the population scores higher than 130 or lower than 70 on standardized intelligence tests.
C) only 5% of the population scores higher than 115 or lower than 85 on standardized intelligence tests.
D) 95% of the population scores between 100 and 130 on standardized intelligence tests.

Question 45

In a normal distribution,____ of the scores fall within plus or minus 1 standard deviation of the mean.

A) 24 percent
B) 50 percent
C) 68 percent
D) 99 percent

Question 46

Which of the following correlation coefficients represents the STRONGEST association between two variables?

A) -.88
B) -.42
C) +.30
D) +.65

Question 47

It is safe to say that the "bedrock" of the scoring system for most psychological tests is the

A) frequency polygon.
B) central tendency.
C) correlation coefficient.
D) normal distribution.

Question 48

On the SAT,the mean is 500 and the standard deviation is 100.If you scored 2 standard deviations above the mean,your score would be

A) 300.
B) 400.
C) 600.
D) 700.

Question 49

High scores on variable X are associated with high scores on variable Y,and low scores on variable X are associated with low scores on variable Y.Hence,the correlation between variables X and Y will be

A) negative.
B) positive.
C) zero.
D) spurious.

Question 50

Which of the following correlation coefficients represents the WEAKEST association between two variables?

A) +.74
B) -.43
C) +.09
D) -.85

Question 51

If you take a test in which the scores are normally distributed and you score at the 40th percentile,you have scored ____ the mean and ____ the median.

A) above; above
B) above; below
C) below; above
D) below; below

Question 52

Frank scored 30 on a test of assertiveness.Assuming that assertiveness is normally distributed with a mean of 20 and a standard deviation of 5,what percentage of people are less assertive than Frank?

A) 50 percent
B) 68.5 percent
C) 95.5 percent
D) 97.5 percent

Question 53

A numerical index of the degree of relationship between two variables is known as the

A) mode.
B) standard deviation.
C) correlation coefficient.
D) mean.

Question 54

The symmetric,bell shaped curve that represents the pattern in which many human characteristics are dispersed in the population is known as a

A) scatter plot.
B) normal distribution.
C) frequency polygon.
D) histogram.

Question 55

When a trait is normally distributed,most scores fall ____ the center of the distribution and the number of scores ____ the center of the distribution.

A) near; gradually decreases away from
B) away from; gradually decreases nearer
C) near; gradually increases away from
D) away from; gradually increases nearer

Question 56

The pattern in which many human characteristics are dispersed in the population that is represented by a symmetrical or bell-shaped curve is referred to as the

A) significant distribution.
B) common distribution.
C) normal distribution.
D) skewed distribution.

Question 57

If you take a test and score at the 70th percentile,you have

A) answered 70 percent of the questions correctly.
B) scored lower than 70 percent of the people taking the test.
C) scored higher than 70 percent of the people taking the test.
D) scored higher than 30 percent of the people taking the test.

Question 58

Julia has an IQ of 130.If the mean for IQ is 100 with a standard deviation of 15,what percentage of the population has an IQ greater than Julia's (assume a normal distribution)?

A) 0 percent
B) 2.5 percent
C) 32 percent
D) 50 percent

Question 59

In a normal distribution,most scores fall near the ____ of the distribution,and the number of scores gradually ____ as one moves away from the mean.

A) low end; increases
B) center; declines
C) center; increases
D) high end; declines

Question 60

An inverse relationship between two variables will yield a

A) negative correlation.
B) positive correlation.
C) weak correlation.
D) spurious correlation.

Question 61

When a correlation is perfect,the data points in a scatter diagram

A) form a bell-shaped curve.
B) fall in a straight line.
C) scatter in a symmetric oval.
D) scatter in a perfect circle.

Question 62

Imagine that Jenilee earned the highest score in the entire class on the midterm exam,and the correlation between midterm exam scores and final exam scores is -0.02.If the final exam grades for Jenilee's class are 92,84,79,65,and 54,

A) Jenilee most likely earned the score of 54.
B) it is impossible to predict Jenilee's final exam score because the correlation coefficient is so small.
C) Jenilee most likely earned the score of 92.
D) Jenilee most likely earned the score of 79.

Question 63

If two variables are correlated,the percentage of variation in one variable that can be predicted from the other variable

A) increases for positive correlations and decreases for negative correlations.
B) increases for negative correlations and decreases for positive correlations.
C) increases as the magnitude of the correlation coefficient increases.
D) decreases as the magnitude of the correlation coefficient increases.

Question 64

Jackie correlates the number of hours spent studying with final grades in a course and finds the correlation is +0.55.When Phil correlates the number of classes missed with final grades in a course,he finds the correlation is -0.75.You should predict that,when the results are plotted using a scatter diagram,

A) Jackie's data points will cluster more tightly than Phil's data points.
B) all Phil's data points will fall on a flat horizontal line running from left to right.
C) Phil's data points will cluster more tightly than Jackie's data points.
D) all Jackie's data points will fall on a vertical line running from top to bottom.

Question 65

If the correlation between intelligence and college grade point average is .60,then intelligence appears to account for about ____ of the variation in grade point average.

A) 40 percent
B) 36 percent
C) 60 percent
D) 90 percent

Question 66

The percentage of variation in one variable that can be predicted based on the other variable is known as the

A) coefficient of determination.
B) standard deviation.
C) correlation coefficient.
D) mean.

Question 67

Stefan has collected a large amount of data in a study designed to test the effectiveness of a new drug meant to slow the progression of Alzheimer's disease.To test whether the drug was effective in a group of participants who received it,in comparison to a group that received a placebo,which type of statistics should Stefan use?

A) descriptive statistics
B) frequency statistics
C) histogram statistics
D) inferential statistics

Question 68

Which of the following correlations will yield the highest coefficient of determination?

A) -.70
B) -.40
C) .30
D) .50

Question 69

Multiplying a correlation coefficient by itself will give you the

A) standard deviation.
B) coefficient of determination.
C) percentile rank.
D) cross-product of the sum of squares.

Question 70

Kurt has collected data on the relationship between the number of hours the employees at a large number of corporate headquarters spend working on their computers and the profits of the corporations.His scatter diagram of the data shows it clusters near a line running from the bottom left corner to the top right corner

A) variable.
B) zero.
C) positive.
D) negative.

Question 71

Eric has collected data on the relationship between the number of hours the employees at a large number of corporate headquarters spend working on their computers and the profits of the corporations.His scatter diagram of the data shows it clusters near a line running from the bottom right corner to the top left corner.This shows the correlation is

A) variable.
B) zero.
C) positive.
D) negative.

Question 72

Inferential statistics are designed to

A) analyze only normally distributed data.
B) summarize large amounts of data.
C) analyze only nonparametric data.
D) help draw conclusions and interpret data.

Question 73

Yolanda has collected data on the relationship between the number of hours the employees at a large number of corporate headquarters spend working on their computers and the profits of the corporations.She finds that the correlation is about positive .75.A scatter diagram of Yolanda's data would show the data

A) on a perfectly straight line from the bottom left corner to the top right corner.
B) clustering near a line running from the bottom left corner to the top right corner.
C) on a perfectly straight line from the bottom right corner to the top left corner.
D) clustering near a line running from the bottom right corner to the top left corner.

Question 74

You find a correlation of .44 between a measure of subjects' extraversion and their reports of how many people they have dated in the last two years.This finding means that

A) 44 percent of extraverts date a lot.
B) extraversion accounts for 44 percent of the variation in the amount of subjects' dating.
C) high extraversion is associated with infrequent dating.
D) high extraversion is associated with more frequent dating.

Question 75

As the magnitude of a correlation coefficient increases,the

A) data points in a scatter diagram become more dispersed.
B) data points in a scatter diagram become less dispersed.
C) correlation coefficient changes from a positive to a negative number.
D) correlation coefficient changes from a negative to a positive number.

Question 76

Nelson's company manufactures computer games,and Nelson is interested in the relationship between the price of a game and people's ratings of the game's quality.He surveys 1000 customers,selected at random,and finds the correlation between price and quality is +0.50.Based on this information,Nelson can conclude that

A) people perceive the quality of a game to be better when the price is high than when the price is low.
B) increasing the price of a game will increase the perceived quality of the game for approximately 50% of consumers.
C) people perceive the quality of a game to be better when the price is low than when the price is high.
D) decreasing the price of a game will increase the perceived quality of the game for approximately 50% of consumers.

Question 77

In a study,a researcher observes a ____ to draw conclusions about a much larger ____.

A) population; sample
B) sample; population
C) sample; sample
D) population; inferential group

Question 78

Manuela has collected data on the relationship between the number of hours the number of days the employees at a large number of factories call in sick and the productivity of the factories.She finds that the correlation is about negative .75.A scatter diagram of Manuela's data would show the data

A) on a perfectly straight line from the bottom left corner to the top right corner.
B) clustering near a line running from the bottom left corner to the top right corner.
C) on a perfectly straight line from the bottom right corner to the top left corner.
D) clustering near a line running from the bottom right corner to the top left corner.

Question 79

Statistics designed to help one draw conclusions from a set of data are referred to as

A) descriptive statistics.
B) frequency statistics.
C) nonparametric statistics.
D) inferential statistics.

Question 80

A graph in which paired X and Y scores for each subject are plotted as single points is called a

A) correlational plot.
B) histogram.
C) frequency distribution.
D) scatter diagram.