Deck 15: Statistical Reasoning in Everyday Life

Question 1

In a group of five individuals,two report annual incomes of $10,000,and the other three report incomes of $14,000,$15,000,and $31,000,respectively.The mode of this group's distribution of annual incomes is

A)$10,000.
B)$15,000.
C)$16,000.
D)$31,000.

Answer 1

$10,000.

Question 2

When Mr.Adams calculated his students' algebra test scores,he noticed that two students had extremely low scores.Which measure of central tendency is affected most by the scores of these two students?

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

Answer 2

mean

Question 3

Seven members of a boys' club reported the following individual earnings from their sale of cookies: $2,$9,$8,$10,$4,$9,and $7.In this distribution of individual earnings

A)the median is greater than the mean and greater than the mode.
B)the median is less than the mean and less than the mode.
C)the median is greater than the mean and less than the mode.
D)the median is less than the mean and greater than the mode.

Answer 3

the median is greater than the mean and less than the mode.

Question 4

A lopsided distribution of scores in which the mean is much larger than both the mode and median is said to be

A)statistically significant.
B)a normal curve.
C)a standard deviation.
D)skewed.

Question 5

The most frequently occurring score in a distribution of scores is the

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

Question 6

For which of the following distributions of scores would the median most clearly be a more appropriate measure of central tendency than the mean?

A)10,22,8,9,6
B)12,6,8,5,4
C)12,15,12,9,12
D)23,7,3,27,16

Question 7

Seven members of a Girl Scout troop report the following individual earnings from their sale of cookies: $4,$1,$7,$6,$8,$2,and $7.In this distribution of individual earnings

A)the mean is less than the mode and equal to the median.
B)the mean is equal to the mode and greater than the median.
C)the mean is greater than the mode and greater than the median.
D)the mean is less than the mode and less than the median.

Question 8

When you read a bar graph,it is most important for you to

A)mentally transform the data into a normal curve.
B)identify the value of the standard deviation.
C)note the range and size of the scale values.
D)remember that correlation aids prediction.

Question 9

Which measure of central tendency is used to calculate the average of your school grades?

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

Question 10

Which of the following is a measure of the degree of variation among a set of scores?

A)mean
B)scatterplot
C)standard deviation
D)correlation coefficient

Question 11

The difference between the highest and lowest scores in a distribution is the

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

Question 12

Although Dominick's psychology class is sometimes longer or shorter than usual,on average each class is 50 minutes.If the lengths of these classes form a normal curve,which statistic would enable Dominick to estimate the probability that any single class will last somewhere between 47 and 53 minutes?

A)range
B)median
C)correlation coefficient
D)standard deviation

Question 13

It's easy to design a ________ to make small differences among groups look large by limiting the range of the y-axis.

A)normal curve
B)scatterplot
C)bar graph
D)standard deviation

Question 14

When an arithmetic average is reported in the news,it is most important for readers to

A)determine whether it is statistically significant.
B)consider whether it is distorted by a few extreme cases.
C)be sure that it represents a standard deviation.
D)assume that it is the midpoint of a normal curve.

Question 15

Evelyn wants to know how consistent her bowling scores have been during the past season.Which of the following measures would tell her what she wants to know?

A)mean
B)median
C)standard deviation
D)correlation coefficient

Question 16

The mean of a distribution of scores is the

A)most frequently occurring score.
B)arithmetic average of all the scores.
C)least frequently occurring score.
D)score exceeded by 50 percent of all the scores.

Question 17

The average price for different brands of toothpaste could be visually displayed in a

A)correlation coefficient.
B)scatterplot.
C)standard deviation.
D)bar graph.

Question 18

Median is to range as central tendency is to

A)skewed distribution.
B)mode.
C)correlation.
D)variation.

Question 19

Central tendency is to variation as ________ is to ________.

A)scatterplot;correlation
B)range;skewed distribution
C)mean;standard deviation
D)median;mode

Question 20

A 2010 U.S.Census report indicated that nearly 65 percent of U.S.households have "below average" income.In this instance,which measure was used to represent the average U.S.household income?

A)range
B)median
C)standard deviation
D)mean

Question 21

The illusion that uncontrollable events are correlated with our actions is fed by a phenomenon known as

A)regression toward the mean.
B)the correlation coefficient.
C)the central tendency.
D)the standard deviation.

Question 22

Which of the following statistical measures is most helpful for indicating the extent to which intelligence test scores can be used to predict grades in school?

A)mean
B)standard deviation
C)correlation coefficient
D)range

Question 23

The symmetrical bell-shaped figure used to represent the distribution of many physical and psychological characteristics is called a

A)bar graph.
B)normal curve.
C)correlation.
D)scatterplot.

Question 24

To represent the correlation between two variables graphically,researchers often construct a

A)skewed distribution.
B)scatterplot.
C)standard deviation.
D)bar graph.

Question 25

Which of the following correlation coefficients expresses the weakest degree of relationship between two variables?

A)-0.12
B)-0.99
C)+0.25
D)-0.50

Question 26

Which of the following is a statistical measure of the relationship between two variables?

A)standard deviation
B)correlation coefficient
C)range
D)mean

Question 27

Professor Connally uses a scatterplot to display the relationship between students' intelligence test scores and the number of failing grades they have received.The points on the scatterplot are most likely clustered in a pattern that

A)resembles a U-shaped curve.
B)extends from the upper left to the lower right.
C)resembles a bell-shaped curve.
D)extends from the lower left to the upper right.

Question 28

If a positive correlation between two sets of scores is displayed in a scatterplot,the points are clustered in a pattern that

A)resembles a bell-shaped curve.
B)extends from the lower left to the upper right of the graph.
C)resembles a U-shaped curve.
D)extends from the upper left to the lower right of the graph.

Question 29

Approximately what percentage of the cases represented by the normal curve fall between -3 and +3 standard deviations from the mean?

A)34
B)68
C)95
D)100

Question 30

Approximately 95 percent of the cases represented by the normal curve fall within ________ standard deviation(s)from the mean.

A)1
B)2
C)3
D)5

Question 31

Which of the following correlations between self-esteem and body weight would enable you to most accurately predict body weight from knowledge of level of self-esteem?

A)+0.60
B)+0.01
C)-0.10
D)-0.06

Question 32

A graphed cluster of dots,each of which represents the values of two factors,is called a

A)bar graph.
B)scatterplot.
C)normal curve.
D)correlation coefficient.

Question 33

Illusory correlation refers to

A)the perception of a relationship between two variables that does not exist.
B)a correlation that exceeds the value of +1.00.
C)a random cluster of points on a scatterplot.
D)the belief that correlations indicate relationships between causes and effects.

Question 34

If a set of standardized test scores is normally distributed,having a mean of 50 and a standard deviation of 10,approximately 68 percent of the group members receive scores somewhere between

A)50 and 60.
B)45 and 55.
C)40 and 60.
D)35 and 65.

Question 35

Approximately what percentage of the cases represented by the normal curve fall between -1 and +1 standard deviations from the mean?

A)16
B)34
C)68
D)95

Question 36

Displaying data in a scatterplot can help us see the extent to which two variables are

A)random samples.
B)normally distributed.
C)correlated.
D)standard deviations.

Question 37

If the points on a scatterplot are clustered in a pattern that extends from the upper left to the lower right,this would suggest that the two variables depicted are

A)normally distributed.
B)positively correlated.
C)negatively correlated.
D)not correlated.

Question 38

A normal curve would approximate the distribution of

A)males and females in the total American population.
B)American children enrolled in each of the first through sixth grades.
C)the physical heights of all American women.
D)all of these data.

Question 39

If IQ scores are normally distributed,having a mean of 100 and a standard deviation of 15,approximately what percentage of people have IQ scores somewhere between 70 and 130?

A)34
B)50
C)68
D)95

Question 40

Gamblers often throw dice gently for low numbers and hard for high numbers.This most directly illustrates

A)an illusion of control.
B)a scatterplot.
C)the normal curve.
D)regression toward the mean.

Question 41

As the size of a representative sample increases,the ________ of that sample is most likely to decrease.

A)range
B)mean
C)standard deviation
D)median

Question 42

Professor Taylor arranged for people of different ages to complete a test of manual dexterity.She then compared manual dexterity across different age levels.The professor's research best illustrates a

A)longitudinal study.
B)normal curve.
C)cross-sectional study.
D)standard deviation.

Question 43

Regression toward the mean refers to the tendency for

A)changes in one factor to predict changes in another factor.
B)unusual events to be followed by more ordinary events.
C)pessimistic thinking to trigger episodes of depression.
D)data to be distributed in a normal curve.

Question 44

Colette received an unusually high grade of A on her first biology test and a B+ on the second,even though she studied equally for both tests.Which of the following best explains Colette's deteriorating pattern of performance?

A)illusory correlation
B)the illusion of control
C)the random sampling effect
D)regression toward the mean

Question 45

A sample average can be used to estimate a population average with greater precision if the sample is

A)large.
B)a skewed distribution.
C)highly variable.
D)vivid and memorable.

Question 46

Researchers studied the effects of vitamin supplements on the health of more than 600 city residents throughout their adulthood.This research procedure best illustrated

A)regression toward the mean.
B)a cross-sectional study.
C)a scatterplot.
D)a longitudinal study.

Question 47

The precision with which a sample average approximates a population average increases as

A)the amount of variability in the sample increases.
B)the amount of variability in the sample decreases.
C)the mean of the sample increases.
D)the mean of the sample decreases.

Question 48

In research studies,psychologists use ________ to decide whether an observed difference between two groups is significant.

A)scatterplots
B)regression toward the mean
C)inferential statistics
D)illusory correlation

Question 49

Statistical reasoning can help us to generalize correctly from a

A)range to a standard deviation.
B)standard deviation to a mean.
C)sample to a population.
D)scatterplot to a skewed distribution.

Question 50

A cross-sectional study is one in which

A)the same people are retested over a period of years.
B)different age groups are tested at the same time.
C)different characteristics of a given individual are assessed at the same time.
D)the behavior of a group is assessed by different researchers.

Question 51

Educational differences between people from different generations partially account for the apparent age-related decline in mental ability found in

A)standard deviations.
B)longitudinal studies.
C)the normal curve.
D)cross-sectional studies.

Question 52

Unusual ESP subjects who defy chance when first tested nearly always lose the supposed "psychic powers" when retested.Parapsychologists have called this

A)illusory correlation.
B)an illusion of control.
C)the decline effect.
D)the normal curve.

Question 53

A longitudinal study is one in which

A)different characteristics of individuals are assessed at the same time.
B)individuals of different ages are compared with one another.
C)the behavior of a group of individuals is assessed by different researchers.
D)the same people are tested and retested over a lengthy period.

Question 54

Longer survival rates of the healthiest and most intelligent people partially account for the apparent stability of intelligence across the life span found in

A)the normal curve.
B)longitudinal studies.
C)standard deviations.
D)cross-sectional studies.

Question 55

In a single day,45 babies were born in hospital X,65 babies in hospital Y,and 25 babies in hospital Z.At which hospital is there the greatest probability that more than 60 percent of the babies are of the same sex?

A)hospital X
B)hospital Y
C)hospital Z
D)The probability is the same at all three hospitals.

Question 56

Which of the following events is the most probable?

A)flipping 6 or more heads in 10 coin flips
B)flipping 60 or more heads in 100 coin flips
C)flipping 600 or more heads in 1000 coin flips
D)All these events are equally probable.

Question 57

To find whether observed differences between samples reflect actual differences between populations,you should determine the ________ of the observed differences.

A)mean
B)median
C)standard deviation
D)statistical significance

Question 58

Differences between two sample averages are most likely to be statistically significant if

A)the difference between the samples is large.
B)the standard deviations of the samples are large.
C)both samples are drawn from the same population.
D)the sample means are larger than the sample medians.

Question 59

After sports magazines give cover-story attention to the recent outstanding performances of an athlete,the individual often suffers a real decline in performance.This may be at least partially explained in terms of

A)illusory correlation.
B)the illusion control.
C)the placebo effect.
D)regression toward the mean.

Question 60

Cross-sectional research indicated that with age,mental ability ________.Longitudinal research indicated that as adults age,intelligence________.

A)remains stable;declines
B)declines;declines
C)declines;remains stable
D)increases;remains stable

Question 61

To provide a rough estimate of how similar or diverse a set of scores is,we should calculate the

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

Question 62

The mode of a distribution of scores is the

A)score exceeded by 50 percent of all the scores.
B)most frequently occurring score.
C)arithmetic average of all the scores.
D)difference between the highest and lowest scores.

Question 63

The arithmetic average of a distribution of scores is the

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

Question 64

The ________ can be a particularly misleading indication of what is average for a ________ distribution of scores.

A)mean;skewed
B)median;skewed
C)mean;normal
D)median;normal

Question 65

A statistically significant difference between two sample groups is NOT likely to be

A)a reflection of differences between the populations they represent.
B)due to chance variation within and between the sample groups.
C)observed more than 5 percent of the time the groups are compared.
D)observed when the two groups are very large.

Question 66

One person in a 10-person group is 10 times older than anyone else in the group.With respect to age,it is most likely that the majority of group members are younger than the group's

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

Question 67

The maximum height of a normal curve corresponds to the ________ of a normal distribution.

A)range
B)mean
C)standard deviation
D)statistical significance

Question 68

Measures of central tendency are most useful for

A)constructing scatterplots.
B)summarizing data with a single score.
C)random sampling.
D)preventing skewed distributions.

Question 69

Ahmed has five sisters who are 3,3,5,9,and 10 years of age.The number 5 represents the ________ of the sisters' ages.

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

Question 70

Which measure of variation is affected most by a few extreme scores?

A)standard deviation
B)mean
C)median
D)range

Question 71

The ________ is a measure of ________.

A)median;variation
B)range;central tendency
C)standard deviation;variation
D)normal curve;central tendency

Question 72

When people's symptoms of emotional distress are at their worst,whatever they do to try to alleviate the condition is likely to be followed by improvement rather than further deterioration.This is best explained in terms of

A)the standard deviation.
B)illusory correlation.
C)the "decline effect."
D)regression toward the mean.

Question 73

Six students spent $10,$13,$2,$12,$13,and $4,respectively,on entertainment.The mode of this group's entertainment expenditures is

A)$9.
B)$11.
C)$12.
D)$13.

Question 74

The mode,median,and mean are measures of

A)central tendency.
B)variation.
C)correlation.
D)statistical significance.

Question 75

The ________ is a measure of ________.

A)standard deviation;central tendency
B)mean;variation
C)median;central tendency
D)mode;variation

Question 76

If a negative correlation between two sets of scores is displayed in a scatterplot,the points are clustered in a pattern that

A)resembles a bell-shaped curve.
B)extends from the lower left to the upper right.
C)resembles a U-shaped curve.
D)extends from the upper left to the lower right.

Question 77

The percentage of students whose average grades fall into various performance levels could be represented by a

A)standard deviation.
B)bar graph.
C)scatterplot.
D)correlation coefficient.

Question 78

To assess age-linked differences in self-esteem,researchers plan to give children from different age groups a test of self-esteem during the upcoming week.This research best illustrates

A)regression toward the mean.
B)a cross-sectional study.
C)a skewed distribution.
D)a longitudinal study.

Question 79

Differences between two samples are LEAST likely to be statistically significant if the samples are _______ and the amount of variability in the samples is _______.

A)small;small
B)large;large
C)small;large
D)large;small

Question 80

Random samples provide ________ estimates of population averages if the scores from the samples have ________.

A)good;small means
B)good;less variability
C)poor;small means
D)poor;less variability