Deck 15: Cousins or Just Good Friends Testing Relationships Using Correlation Coefficient

Question 1

Correlation coefficients can test _______ variable(s) at a time.

A)only one
B)only two
C)one or more
D)two or more

Answer 1

B

Question 2

Correlation coefficients examine ______.

A)differences between two groups
B)differences between two or more groups
C)the relationship between variables
D)how variables can be arranged into higher-order factors

Answer 2

C

Question 3

What is the most important characteristic of a correlation coefficient?

A)number of variables included
B)absolute value
C)one tailed
D)two tailed

Answer 3

B

Question 4

When computing the correlation coefficient, the _______ between variables, not the _______ between groups, is being examined.

A)relationship; difference
B)difference; relationship
C)means, reliability
D)reliability; means

Question 5

Correlations can be _______.

A)directional or nondirectional
B)only directional
C)only nondirectional
D)neither directional nor nondirectional

Question 6

If the correlation between two variables is .496, how much of the variance has not been accounted for?

A)24.6%
B)49.6%
C)50.4%
D)75.4%

Question 7

Which of the following is the appropriate method for calculating the degrees of freedom associated with a correlation coefficient?

A)n − 1
B)n − 2
C)n − 3
D)n − 4

Question 8

What is another term for a negative correlation?

A)indirect
B)nondirectional
C)direct
D)unidirectional

Question 9

The level of risk or Type I error typically set for testing the level of significance of a correlation coefficient is which of the following?

A).01
B).05
C).95
D).99

Question 10

If you do not predict that a relationship between two variables will be either positive or negative, what type of test should you use?

A)two tailed
B)ANOVA
C)one tailed
D)Cohen's d

Question 11

While you can use the correlation coefficient as its own test statistic, what is the other appropriate test statistic often used to examine the significance of a correlation?

A)F-test
B)Cohen's d
C)t-test
D)ꞃ²

Question 12

If you posit that a relationship between two variables will be either positive or negative, what type of test should you use?

A)two tailed
B)ANOVA
C)one tailed
D)Cohen's d

Question 13

The correlation coefficient is a measure of _______.

A)mean differences
B)causation
C)prediction
D)association

Question 14

Which of the following is another use of correlation coefficients?

A)testing mean differences
B)testing causal relationships
C)estimating reliability
D)estimating power

Question 15

Significant correlations are not able to indicate _______.

A)the probability level
B)the size of the effect
C)causality
D)the strength of the effect

Question 16

What is another term for a positive correlation?

A)indirect
B)nondirectional
C)direct
D)unidirectional

Question 17

In the formula for calculating degrees of freedom for a correlation coefficient, what does the n represent?

A)sample size
B)number of groups
C)number of pairs
D)population

Question 18

This chapter illustrates that you can also incorporate _____ into the correlation coefficient.

A)statistical significance
B)substantial significance
C)descriptive statistics
D)generalizability

Question 19

The appropriate test statistic to use is the _______.

A)t-test for the correlation coefficient
B)p-test for the correlation coefficient
C)r-test for the correlation coefficient
D)t-test for statistical significance

Question 20

What is the name of the Greek letter ρ?

A)phi
B)rho
C)chi
D)alpha

Question 21

What does the statement rₓᵧ ≠ 0 represent?

A)null hypothesis
B)t statistic
C)mean difference
D)research hypothesis

Question 22

When computing a correlation coefficient, if you have 27 degrees of freedom, your sample size must be _______.

A)29
B)27
C)25
D)26

Question 23

If the correlation between two variables is .496, what is the coefficient of determination?

A).246
B).496
C).504
D).754

Question 24

A professor hypothesizes that there will be a positive relationship between couples' listening skills and length of marriage.She has a _______.

A)one-tailed hypothesis
B)invalid hypothesis
C)valid hypothesis
D)two-tailed hypothesis

Question 25

In the equation r₍₆₅₎ = .45, p < .05, what are the degrees of freedom?

A).45
B)45
C).65
D)65

Question 26

If a simple Pearson correlation value = .685, what percentage of variance is accounted for?

A)35%
B)47%
C)68%
D)69%

Question 27

In the equation r₍₆₅₎ = .45, p < .05, what is the obtained value?

A).45
B)45
C).65
D)65

Question 28

If you were looking to examine the relationship between chocolate sales and student happiness, you could test the relationship using the _______.

A)mean difference
B)t statistic
C)error difference
D)c statistic

Question 29

You would like to examine the association between temperature and frozen yogurt sales.You hypothesize that higher temperatures will be associated with increased frozen yogurt sales.You have a _______.

A)one-tailed hypothesis
B)two-tailed hypothesis
C)nondirectional hypothesis
D)invalid hypothesis

Question 30

If a research hypothesis does not predict the direction of a relationship, the test is _______.

A)one tailed
B)two tailed
C)direct
D)positive

Question 31

If a simple Pearson correlation value = .75, what percentage of variance is unaccounted for?

A)25%
B)44%
C)56%
D)75%

Question 32

Which of the following indicates a nonsignificant correlation?

A)p < .05
B)p < .01
C)p = .02
D)p = .30

Question 33

A professor hypothesizes that there will be a relationship between couples' listening skills and length of marriage.She has a _______.

A)one-tailed hypothesis
B)invalid hypothesis
C)valid hypothesis
D)two-tailed hypothesis

Question 34

When computing a correlation coefficient, if you have 36 degrees of freedom, your sample size must be _______.

A)35
B)34
C)38
D)37

Question 35

If a research hypothesis posits that there is a direct relationship between two variables, the test is _______.

A)one tailed
B)two tailed
C)negative
D)nondirectional

Question 36

If a simple Pearson correlation value = .362, what percentage of variance is unaccounted for?

A)25%
B)36%
C)56%
D)87%

Question 37

If a simple Pearson correlation value = .512, what percentage of variance is accounted for?

A)26%
B)49%
C)51%
D)74%

Question 38

Which of the following indicates a significant correlation?

A)p = .21
B)p < .05
C)p < .20
D)p < .50

Question 39

In the equation r₍₆₅₎ = .45, p < .05, what does r represent?

A)observed statistic
B)experimental statistic
C)test statistic
D)critical statistic

Question 40

When computing a correlation coefficient, if you have 55 degrees of freedom, your sample size must be _______.

A)55
B)53
C)56
D)57

Question 41

Which of the following indicates a very significant correlation?

A)p = .05
B)p < .05
C)p < .01
D)p < .50

Question 42

If the accounted variance is 24.2%, what is the correlation between the two variables?

A)24.6%
B)49.2%
C)50.4%
D)75.4%

Question 43

If the correlation between two variables is .876, how much of the variance has been accounted for?

A)24.6%
B)49.6%
C)59.1%
D)76.7%

Question 44

A correlation coefficient can only test one variable at a time.

Question 45

If a research hypothesis predicts the direction of a relationship, the test is _______.

A)one tailed
B)two tailed
C)direct
D)positive

Question 46

If the coefficient of determination is .767, what is correlation between the two variables?

A).246
B).496
C).504
D).876

Question 47

If the correlation between two variables is .767, how much variance has not been accounted for?

A).246
B).412
C).588
D).876

Question 48

Correlation coefficients examine the relationship between variables.

Question 49

The correlation between the two variables of interest is .81, which is significant at the .0337 level.That means ______.

A)The null hypothesis is rejected.
B)The research hypothesis is accepted.
C)The null hypothesis is accepted.
D)It cannot be determined.

Question 50

With regard to correlations, tests can be either directional or nondirectional.

Question 51

A significant correlation does not indicate causality.

Question 52

A _______ correlation is also known as a _______ correlation.

A)negative; direct
B)negative; nondirectional
C)positive; direct
D)positive; nondirectional

Question 53

If the hypothesis shows no direction, what type of correlation coefficient should we use?

A)partial correlation
B)absolute value
C)one tailed
D)two tailed

Question 54

The correlation between the two variables of interest is .081, which is significant at the .637 level.That means ______.

A)The null hypothesis is rejected.
B)The research hypothesis is accepted.
C)The null hypothesis is accepted.
D)It cannot be determined.

Question 55

What is another term for an indirect correlation?

A)negative
B)nondirectional
C)positive
D)unidirectional

Question 56

Statistically significant correlations cannot show _______.

A)the probability level
B)the size of the effect
C)causality
D)the strength of the effect

Question 57

The appropriate test statistic to use is the t-test for the correlation coefficient.

Question 58

If a research hypothesis posits that there is a nondirect relationship between two variables, the test is _______.

A)one tailed
B)two tailed
C)negative
D)nondirectional

Question 59

A ______ correlation is also known as a ______ correlation.

A)negative; indirect
B)negative; nondirectional
C)positive; indirect
D)positive; nondirectional

Question 60

What is another term for a direct correlation?

A)positive
B)nondirectional
C)negative
D)unidirectional

Question 61

If two variables are significantly correlated, this means that one variable causes the other.

Question 62

Write an example of a null hypothesis for a t-test for the correlation coefficient.

Question 63

Correlations can be used to examine the differences between groups.

Question 64

The research hypothesis posits that there will be a relationship between the number of hours a student studies and their result on a test (H₁: rₓᵧ ≠ 0).What would be concluded for r₍₄₅₎ = .213, p > .05?

Question 65

Write an example of a research hypothesis for a one-tailed t-test for the correlation coefficient.

Question 66

The research hypothesis posits that the relationship between two variables will be greater than zero (H₁: rₓᵧ > 0).What would be concluded for r₍₂₉₎ = .467, p < .05?

Question 67

Give an example of a one-tailed hypothesis that may be tested through a correlation.

Question 68

Write an example of a research hypothesis for a two-tailed t-test for the correlation coefficient.

Question 69

The research hypothesis posits that the more caffeine consumed by a subject, the longer a subject will stay awake (H₁: rₓᵧ > 0).What would be concluded for r₍₁₀₎= .653, p < .05?

Question 70

A single correlation can be computed in order to determine the relationship between three variables.

Question 71

A significant correlation indicates a meaningful relationship.

Question 72

The correlation coefficient can only be used for one-tailed tests.

Question 73

Think about the t-test for the correlation coefficient.Write the equations for a research hypothesis with a one-tailed test and for a research hypothesis with a two-tailed test.Write the equation for the null hypothesis.

Question 74

Give an example of a situation when it would be appropriate to use the t-test for the correlation coefficient test statistic.

Question 75

What are the eight steps involved when examining a research question?