Question 1

Correlation coefficients examine the relationship between variables.

Accepted Answer

Correlation coefficients measure the strength and direction of the linear relationship between two variables.

Question 2

Another term for a direct correlation is ______
A)a positive correlation
B)a nondirectional correlation
C)a negative correlation
D)a unidirectional correlation

Accepted Answer

A direct correlation means that as one variable increases, the other variable increases as well. This is also known as a positive correlation. Option B is incorrect because a nondirectional correlation refers to a situation where two variables are related but we do not know the direction of the relationship. Option C is incorrect because a negative correlation means that as one variable increases, the other variable decreases. Option D is incorrect because a unidirectional correlation is not a commonly used term in statistics.

Question 3

When you hypothesize that there will be a relationship between couples' listening skills and length of marriage,you have a ______.
A)one-tailed hypothesis
B)invalid hypothesis
C)valid hypothesis
D)two-tailed hypothesis

Accepted Answer

A two-tailed hypothesis is used when predicting a relationship between variables without specifying the direction of the relationship. Since the hypothesis about couples' listening skills and length of marriage does not specify how the skills affect the length (whether positively or negatively), it is considered two-tailed.

Question 4

The correlation between the two variables of interest is 0.81,which is significant at the 0.0337 level.That means ______.
A)that the null hypothesis is rejected
B)that the research hypothesis is rejected
C)that the null hypothesis is accepted
D)that the null hypothesis cannot be determined

Accepted Answer

A correlation coefficient of 0.81 signifies a strong positive relationship between the two variables. Since the correlation is significant at the 0.0337 level, it means that the probability of obtaining this correlation coefficient by chance if the null hypothesis is true (i.e., no relationship between variables) is less than or equal to 0.0337. Therefore, we reject the null hypothesis and conclude that there is a significant relationship between the two variables.

Question 5

When the 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

Accepted Answer

When a research hypothesis suggests a nondirect relationship between two variables, it implies that the direction of the relationship is not specified. This situation calls for a two-tailed test, which is used to determine if there is any significant relationship between the variables, regardless of the direction of the relationship.

Question 6

The correlation between the two variables of interest is 0.081,which is significant at the 0.637 level.This means ______.
A)that the null hypothesis is rejected
B)that the research hypothesis is accepted
C)that the null hypothesis is accepted
D)that the null hypothesis cannot be determined

Accepted Answer

The significance level of 0.637 is higher than the typical threshold of 0.05 for rejecting the null hypothesis. Therefore, we fail to reject the null hypothesis and conclude that there is no significant correlation between the two variables of interest.

Question 7

When the research hypothesis predicts the direction of a relationship,the test is ______.
A)one-tailed
B)two-tailed
C)direct
D)positive

Accepted Answer

When the research hypothesis predicts the direction of a relationship, the test is one-tailed. This is because the hypothesis is only looking for an effect in one direction, rather than both directions (which would be a two-tailed test). The terms "direct" and "positive" do not necessarily refer to whether the hypothesis predicts a specific direction, so they are not the best choices for this question.

Question 8

Another term for an indirect correlation is ______
A)a negative correlation
B)a nondirectional correlation
C)a positive correlation
D)a unidirectional correlation

Accepted Answer

An indirect correlation is another term for a negative correlation, where as one variable increases, the other decreases.

Question 9

A ______ correlation is also known as a ______ correlation.
A)negative;indirect
B)negative;nondirectional
C)positive;indirect
D)positive;nondirectional

Accepted Answer

A negative correlation is also known as an indirect correlation, where an increase in one variable leads to a decrease in the other variable.

Question 10

A ______ correlation is also known as a ______ correlation.
A)negative;direct
B)negative;nondirectional
C)positive;direct
D)positive;nondirectional

Accepted Answer

A positive correlation is also known as a direct correlation, as both variables move in the same direction. Negative correlation is the opposite, with variables moving in opposite directions. Nondirectional does not accurately describe a type of correlation.

Question 11

Statistically significant correlations cannot show ______.
A)the probability level
B)the size of the effect
C)causality
D)the strength of the effect

Accepted Answer

Statistically significant correlations can only show that there is a relationship between two variables, but they cannot determine causality.

Question 12

If the hypothesis shows no direction,what type of correlation coefficient should be used?
A)partial correlation
B)absolute value
C)one-tailed
D)two-tailed

Accepted Answer

A two-tailed correlation coefficient is appropriate when the hypothesis does not specify a direction of the relationship between the variables. This is because a two-tailed test allows for the possibility of a positive or negative correlation.

Question 13

Which of the following indicates a very significant correlation?
A)p = 0.05
B)p < 0.05
C)p < 0.01
D)p < 0.50

Accepted Answer

A p-value less than 0.01 indicates a very significant correlation. The other options indicate less significant or non-significant correlations.

Question 14

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%

Accepted Answer

The accounted variance is the square of the correlation coefficient (r^2). To find the correlation coefficient (r), take the square root of the accounted variance. √0.242 = 0.492 or 49.2%.

Question 15

If the correlation between two variables is 0.876,how much of the variance has been accounted for?
A)24.6%
B)49.6%
C)59.1%
D)76.7%

Accepted Answer

The coefficient of determination (r-squared) gives the proportion of variance in one variable that can be explained by the other variable. Squaring the correlation coefficient gives us the coefficient of determination, which in this case is (0.876)^2 = 0.767, or 76.7%. Therefore, the answer is D.

Question 16

If the coefficient of determination is 0.767,what is correlation between the two variables?
A)0.246
B)0.496
C)0.504
D)0.876

Accepted Answer

The coefficient of determination is also known as R-squared and is the square of the correlation coefficient (r). 
R-squared = 0.767
r^2 = 0.767
r = sqrt(0.767) = 0.876 
Therefore, the correlation between the two variables is 0.876, which is best represented by choice D.

Question 17

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

Accepted Answer

A correlation coefficient can test the relationship between two variables, not just one.

Question 18

A researcher hypothesizes that there will be a positive relationship between couples' listening skills and length of marriage.The researcher has a ______.
A)one-tailed hypothesis
B)invalid hypothesis
C)valid hypothesis
D)two-tailed hypothesis

Accepted Answer

The hypothesis predicts a specific direction of the relationship (positive), which is characteristic of a one-tailed hypothesis.

Question 19

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

Accepted Answer

The answer of When computing a correlation coefficient,if you have...

Question 20

If the correlation between two variables is 0.767,how much variance has not been accounted for?
A)0.246
B)0.412
C)0.588
D)0.876

Accepted Answer

The correlation coefficient squared (0.767^2 = 0.588) represents the proportion of variance that has been accounted for. Therefore, the proportion of variance that has not been accounted for is 1 - 0.588 = 0.412.

Quiz 15: Testing Relationships Using the Correlation Coefficients: Cousins or Just Good Friends

Correlation coefficients examine the relationship between variables.

Another term for a direct correlation is ______

When you hypothesize that there will be a relationship between couples' listening skills and length of marriage,you have a ______.

The correlation between the two variables of interest is 0.81,which is significant at the 0.0337 level.That means ______.

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

The correlation between the two variables of interest is 0.081,which is significant at the 0.637 level.This means ______.

When the research hypothesis predicts the direction of a relationship,the test is ______.

Another term for an indirect correlation is ______

A correlation is also known as a correlation.

A correlation is also known as a correlation.

Statistically significant correlations cannot show ______.

If the hypothesis shows no direction,what type of correlation coefficient should be used?

Which of the following indicates a very significant correlation?

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

If the correlation between two variables is 0.876,how much of the variance has been accounted for?

If the coefficient of determination is 0.767,what is correlation between the two variables?

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

A researcher hypothesizes that there will be a positive relationship between couples' listening skills and length of marriage.The researcher has a ______.

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

If the correlation between two variables is 0.767,how much variance has not been accounted for?