Question 1

A newspaper headline writer found that the more adjectives she put in the titles of her articles, the greater the number of newspapers that were sold that day. This relationship between numbers of adjectives and newspaper sales must be

Accepted Answer

A)   significantly positive.
B)   significantly negative.
C)   monotonic.
D)   positive.E) All of the above
F) B) and D)

Question 2

When we use heterogeneous subsamples of data, such as older and younger subjects, the resulting correlation between intelligence and education could

Accepted Answer

A)   tell you more about the relationship between Age and Education than between Intelligence and Education.
B)   be very misleading.
C)   represent the relationship between Education and Intelligence accurately.
D)   all of the aboveE) B) and C)
F) A) and D) D

Question 3

A reliable correlation is one that

Accepted Answer

A)   is significantly different from 0.
B)   is likely to be closely approximated in a future study.
C)   is close to 1.00.
D)   is non-negative.E) None of the above
F) C) and D)

Question 4

Point biseral correlation is used when one of the variables is dichotomous.

Accepted Answer

A) True 
 B)False

Question 5

The data illustrated in the graph below suggest

Accepted Answer

A)   that there is a strong positive relationship between height and weight.
B)   that there is no relationship between height and weight.
C)   that some other variable is involved in the relationship.
D)   that these data are unreliable.E) C) and D)
F) None of the above

Question 6

An intercorrelation matrix is one that

Accepted Answer

A)   presents the correlations of each variable with each other variable.
B)   is symmetric.
C)   has as many rows as it does columns.
D)   all of the aboveE) All of the above
F) B) and D)

Question 7

Correlations are typically used to examine mean differences between groups.

Accepted Answer

A) True 
 B)False

Question 8

A significant correlation is one which

Accepted Answer

A)   has a great deal of meaning.
B)   means that the variables are not linearly independent.
C)   is very hard to find.
D)   is most likely to occur when the true correlation is near 0.E) A) and D)
F) B) and C)

Question 9

A curvilinear relationship is one in which

Accepted Answer

A)   one variable always increases as the other increases.
B)   as X increases, Y will increase and then level off or fall.
C)   as X increases, Y will decrease and then level off or rise.
D)   both b and cE) A) and D)
F) A) and C)

Question 10

Restricted range has no effect on correlation coefficients.

Accepted Answer

A) True 
 B)False

Question 11

The difference between a point biserial coefficient and a normal Pearson correlation coefficient is that

Accepted Answer

A)   a point biserial correlation is based on two continuous variables.
B)   a point biserial correlation is based on one dichotomous variable and one continuous variable.
C)   a point biserial correlation is based on two dichotomous variables.
D)   the kind of variable has nothing to do with the issue.E) None of the above
F) All of the above B

Question 12

The example showing a negative relationship between speed and accuracy tells us that

Accepted Answer

A)   the slowest responders are always the most accurate.
B)   the fastest responders are always the most accurate.
C)   on average, slower responders are more accurate than faster responders.
D)   speed is a virtue.E) B) and C)
F) A) and D) C

Question 13

Correlation cannot be used to test associations between two dichotomous variables.

Accepted Answer

A) True 
 B)False

Question 14

In the scatterplot for the data in the previous question, the biggest outliers are likely to be

Accepted Answer

A)   Portugal and Sweden.
B)   Japan and Ireland .
C)   Denmark and Sweden.
D)   the U.S.A. and West Germany.E) A) and B)
F) All of the above

Question 15

Correlation coefficients can range from -1 to 1.

Accepted Answer

A) True 
 B)False

Question 16

In testing the significance of a correlation coefficient, the degrees of freedom are

Accepted Answer

A)   N
B)   N - 1
C)   N - 2
D)   N - 3E) A) and B)
F) None of the above

Question 17

Professor Falls wants to determine if there is a relationship between frequent hearing of a startle stimulus and hearing loss. He ran a regression and obtained an r value of .60. Which of the following best summarizes what this result means?

Accepted Answer

A)   60% of hearing loss is accounted for by frequency of hearing startle stimuli.
B)   36% of the variability in hearing loss can be accounted for by variability in the hearing of startle stimuli.
C)   36% of startle stimuli cause hearing loss.
D)   60% of hearing loss is caused by startle stimuli.E) A) and B)
F) None of the above

Question 18

Which of the following represents a closer relationship between two variables?

Accepted Answer

A)   r = .00
B)   r = .50
C)   r = -.30
D)   r = -.65E) A) and C)
F) None of the above

Question 19

Which r-value represents the strongest correlation?

Accepted Answer

A)   +.50
B)   -.50
C)   -.75
D)   1.65E) B) and D)
F) A) and B)

Question 20

The correlation between two variables is a measure of the degree to which

Accepted Answer

A)   points cluster together around some best-fitting straight line.
B)   differences in one variable can be predicted from differences in the other variable.
C)   one variable varies with the other variable.
D)   all of the aboveE) C) and D)
F) A) and D)

Exam 9: Correlation

A newspaper headline writer found that the more adjectives she put in the titles of her articles, the greater the number of newspapers that were sold that day. This relationship between numbers of adjectives and newspaper sales must be

Correct AnswerverifiedShow Answer

When we use heterogeneous subsamples of data, such as older and younger subjects, the resulting correlation between intelligence and education could

Correct AnswerverifiedD

A reliable correlation is one that

Correct AnswerverifiedShow Answer

Point biseral correlation is used when one of the variables is dichotomous.

Correct AnswerverifiedShow Answer

The data illustrated in the graph below suggest

Correct AnswerverifiedShow Answer

An intercorrelation matrix is one that

Correct AnswerverifiedShow Answer

Correlations are typically used to examine mean differences between groups.

Correct AnswerverifiedShow Answer

A significant correlation is one which

Correct AnswerverifiedShow Answer

A curvilinear relationship is one in which

Correct AnswerverifiedShow Answer

Restricted range has no effect on correlation coefficients.

Correct AnswerverifiedShow Answer

The difference between a point biserial coefficient and a normal Pearson correlation coefficient is that

Correct AnswerverifiedB

The example showing a negative relationship between speed and accuracy tells us that

Correct AnswerverifiedC

Correlation cannot be used to test associations between two dichotomous variables.

Correct AnswerverifiedShow Answer

In the scatterplot for the data in the previous question, the biggest outliers are likely to be

Correct AnswerverifiedShow Answer

Correlation coefficients can range from -1 to 1.

Correct AnswerverifiedShow Answer

In testing the significance of a correlation coefficient, the degrees of freedom are

Correct AnswerverifiedShow Answer

Professor Falls wants to determine if there is a relationship between frequent hearing of a startle stimulus and hearing loss. He ran a regression and obtained an r value of .60. Which of the following best summarizes what this result means?

Correct AnswerverifiedShow Answer

Which of the following represents a closer relationship between two variables?

Correct AnswerverifiedShow Answer

Which r-value represents the strongest correlation?

Correct AnswerverifiedShow Answer

The correlation between two variables is a measure of the degree to which

Correct AnswerverifiedShow Answer

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