Question 1

How large a sample is needed for a correlation of r = 0.550 to be significant using a two-tailed test with α = .05?

Accepted Answer

A) n = 14 
B) n = 13 
C) n = 12 
D) n = 11 
A) n = 14 
B) n = 13 
C) n = 12 
D) n = 11 A

Question 2

For a group of graduating college seniors, a researcher records each student's rank in his/her high school graduating class and the student's rank in the college graduating class.Which correlation should be used to measure the relationship between these two variables?

Accepted Answer

A) Pearson correlation 
B) Spearman correlation 
C) point-biserial correlation 
D) phi-coefficient 
A) Pearson correlation 
B) Spearman correlation 
C) point-biserial correlation 
D) phi-coefficient B

Question 3

For a two-tailed hypothesis test evaluating the significance of a correlation, the null hypothesis states that the sample correlation is zero.

Accepted Answer

A) True 
 B)False  False

Question 4

For which of the following Pearson correlations would the data points be clustered most closely around a straight line?

Accepted Answer

A) r = -0.10 
B) r = +0.40 
C) r = -0.70 
D) There is no relationship between the correlation and how close the points are to a straight line. 
A) r = -0.10 
B) r = +0.40 
C) r = -0.70 
D) There is no relationship between the correlation and how close the points are to a straight line.

Question 5

A researcher obtains SSX = 20, SSY = 5, and SP = 7 for a set of n = 25 pairs of scores.The Pearson correlation for these scores is r = 7/10 = 0.70.

Accepted Answer

A) True 
 B)False

Question 6

If the data points in a scatter plot show a nearly circular pattern, then the correlation is near zero.

Accepted Answer

A) True 
 B)False

Question 7

Assuming that other factors are constant, a correlation of r = -0.95 will result in more accurate predictions than a correlation of r = +0.70.

Accepted Answer

A) True 
 B)False

Question 8

In a test for significance of a Pearson correlation for a sample of n = 30 individuals, you determine the critical value by using df = 29.

Accepted Answer

A) True 
 B)False

Question 9

Which correlation should be used to measure the relationship between gender and grade point average for a group of college students?

Accepted Answer

A) Pearson correlation 
B) Spearman correlation 
C) point-biserial correlation 
D) phi-coefficient 
A) Pearson correlation 
B) Spearman correlation 
C) point-biserial correlation 
D) phi-coefficient

Question 10

The Spearman correlation is used to measure the relationship when both variables have been measured on an ordinal scale (both are ranks).

Accepted Answer

A) True 
 B)False

Question 11

What would the scatterplot show for data that produce a Pearson correlation of r = +.88?

Accepted Answer

A) points clustered close to a line that slopes up to the right 
B) points clustered close to a line that slopes down to the right 
C) points widely scattered around a line that slopes up to the right 
D) points widely scattered around a line that slopes down to the right 
A) points clustered close to a line that slopes up to the right 
B) points clustered close to a line that slopes down to the right 
C) points widely scattered around a line that slopes up to the right 
D) points widely scattered around a line that slopes down to the right

Question 12

The value for a correlation can never be greater than +1.00.

Accepted Answer

A) True 
 B)False

Question 13

A researcher classifies people by gender and by whether or not they routinely watch the evening news on television.For the resulting data, the correct method for measuring the relationship between the two variables would be the phi-coefficient.

Accepted Answer

A) True 
 B)False

Question 14

The Pearson and the Spearman correlations are both computed for the same set of data.If the Spearman correlation is rS = +1.00, then what can you conclude about the Pearson correlation?

Accepted Answer

A) It will be positive. 
B) It will have a value of 1.00 
C) It will be positive and have a value of 1.00 
D) There is no predictable relationship between the Pearson and the Spearman correlations 
A) It will be positive. 
B) It will have a value of 1.00 
C) It will be positive and have a value of 1.00 
D) There is no predictable relationship between the Pearson and the Spearman correlations

Question 15

For a two-tailed hypothesis test evaluating a Pearson correlation, what is stated by the null hypothesis?

Accepted Answer

A) there is a non-zero correlation for the general population 
B) the population correlation is zero 
C) there is a non-zero correlation for the sample 
D) the sample correlation is zero 
A) there is a non-zero correlation for the general population 
B) the population correlation is zero 
C) there is a non-zero correlation for the sample 
D) the sample correlation is zero

Question 16

A set of n = 15 pairs of scores (X and Y values) has SSX = 4, SSY = 25, and SP = 6.The Pearson correlation for these data is

Accepted Answer

A) 6/100 
B) 6/10 
C) 6/(100/15) 
D) 6/(10/√15) 
A) 6/100 
B) 6/10 
C) 6/(100/15) 
D) 6/(10/√15)

Question 17

What is indicated by a Pearson correlation of r = +1.00 between X and Y?

Accepted Answer

A) each time X increases, there is a perfectly predictable increase in Y 
B) every change in X causes a change in Y 
C) every increase in X causes an increase in Y 
D) All of the other 3 choices occur with a correlation of +1.00. 
A) each time X increases, there is a perfectly predictable increase in Y 
B) every change in X causes a change in Y 
C) every increase in X causes an increase in Y 
D) All of the other 3 choices occur with a correlation of +1.00.

Question 18

The value for the sum of products (SP) is always greater than or equal to zero.

Accepted Answer

A) True 
 B)False

Question 19

What is indicated by a positive value for a correlation?

Accepted Answer

A) increases in X tend to be accompanied by increases in Y 
B) increases in X tend to be accompanied by decreases in Y 
C) a much stronger relationship than if the correlation were negative 
D) a much weaker relationship than if the correlation were negative 
A) increases in X tend to be accompanied by increases in Y 
B) increases in X tend to be accompanied by decreases in Y 
C) a much stronger relationship than if the correlation were negative 
D) a much weaker relationship than if the correlation were negative

Question 20

A researcher obtains a Pearson correlation of r = 0.43 for a sample of n = 20 participants.For a two-tailed test, which of the following accurately describes the significance of the correlation?

Accepted Answer

A) The correlation is significant with α = .05 but not with α = .01. 
B) The correlation is significant with either α = .05 or α = .01. 
C) The correlation is not significant with either α = .05 or α = .01. 
D) There is not enough information to evaluate the significance of the correlation. 
A) The correlation is significant with α = .05 but not with α = .01. 
B) The correlation is significant with either α = .05 or α = .01. 
C) The correlation is not significant with either α = .05 or α = .01. 
D) There is not enough information to evaluate the significance of the correlation.

How large a sample is needed for a correlation of r = 0.550 to be significant using a two-tailed test with α = .05?

For a group of graduating college seniors, a researcher records each student's rank in his/her high school graduating class and the student's rank in the college graduating class.Which correlation should be used to measure the relationship between these two variables?

For a two-tailed hypothesis test evaluating the significance of a correlation, the null hypothesis states that the sample correlation is zero.

For which of the following Pearson correlations would the data points be clustered most closely around a straight line?

A researcher obtains SS_X = 20, SS_Y = 5, and SP = 7 for a set of n = 25 pairs of scores.The Pearson correlation for these scores is r = 7/10 = 0.70.

If the data points in a scatter plot show a nearly circular pattern, then the correlation is near zero.

Assuming that other factors are constant, a correlation of r = -0.95 will result in more accurate predictions than a correlation of r = +0.70.

In a test for significance of a Pearson correlation for a sample of n = 30 individuals, you determine the critical value by using df = 29.

Which correlation should be used to measure the relationship between gender and grade point average for a group of college students?

The Spearman correlation is used to measure the relationship when both variables have been measured on an ordinal scale (both are ranks).

What would the scatterplot show for data that produce a Pearson correlation of r = +.88?

The value for a correlation can never be greater than +1.00.

A researcher classifies people by gender and by whether or not they routinely watch the evening news on television.For the resulting data, the correct method for measuring the relationship between the two variables would be the phi-coefficient.

The Pearson and the Spearman correlations are both computed for the same set of data.If the Spearman correlation is r_S = +1.00, then what can you conclude about the Pearson correlation?

For a two-tailed hypothesis test evaluating a Pearson correlation, what is stated by the null hypothesis?

A set of n = 15 pairs of scores (X and Y values) has SS_X = 4, SS_Y = 25, and SP = 6.The Pearson correlation for these data is

What is indicated by a Pearson correlation of r = +1.00 between X and Y?

The value for the sum of products (SP) is always greater than or equal to zero.

What is indicated by a positive value for a correlation?

A researcher obtains a Pearson correlation of r = 0.43 for a sample of n = 20 participants.For a two-tailed test, which of the following accurately describes the significance of the correlation?

Introduction to Statistics

Frequency Distributions

Central Tendency

Variability

Z-Scores

Probability

The Distribution of Sample Means

Introduction to Hypothesis Testing

Introduction to the T Statistic

The T Test for Two Independent Samples

The T Test for Two Related Samples

Introduction to Analysis of Variance

Repeated-Measures Anova

Two-Factor Analysis of Variance

Introduction to Regression

Chi-Square Tests

The Binomial Test

Choosing the Right Statistics

Filters

Exam 15: Correlation

How large a sample is needed for a correlation of r = 0.550 to be significant using a two-tailed test with α = .05?

For a group of graduating college seniors, a researcher records each student's rank in his/her high school graduating class and the student's rank in the college graduating class.Which correlation should be used to measure the relationship between these two variables?

For a two-tailed hypothesis test evaluating the significance of a correlation, the null hypothesis states that the sample correlation is zero.

For which of the following Pearson correlations would the data points be clustered most closely around a straight line?

A researcher obtains SSX = 20, SSY = 5, and SP = 7 for a set of n = 25 pairs of scores.The Pearson correlation for these scores is r = 7/10 = 0.70.

If the data points in a scatter plot show a nearly circular pattern, then the correlation is near zero.

Assuming that other factors are constant, a correlation of r = -0.95 will result in more accurate predictions than a correlation of r = +0.70.

In a test for significance of a Pearson correlation for a sample of n = 30 individuals, you determine the critical value by using df = 29.

Which correlation should be used to measure the relationship between gender and grade point average for a group of college students?

The Spearman correlation is used to measure the relationship when both variables have been measured on an ordinal scale (both are ranks).

What would the scatterplot show for data that produce a Pearson correlation of r = +.88?

The value for a correlation can never be greater than +1.00.

A researcher classifies people by gender and by whether or not they routinely watch the evening news on television.For the resulting data, the correct method for measuring the relationship between the two variables would be the phi-coefficient.

The Pearson and the Spearman correlations are both computed for the same set of data.If the Spearman correlation is rS = +1.00, then what can you conclude about the Pearson correlation?

For a two-tailed hypothesis test evaluating a Pearson correlation, what is stated by the null hypothesis?

A set of n = 15 pairs of scores (X and Y values) has SSX = 4, SSY = 25, and SP = 6.The Pearson correlation for these data is

What is indicated by a Pearson correlation of r = +1.00 between X and Y?

The value for the sum of products (SP) is always greater than or equal to zero.

What is indicated by a positive value for a correlation?

A researcher obtains a Pearson correlation of r = 0.43 for a sample of n = 20 participants.For a two-tailed test, which of the following accurately describes the significance of the correlation?

Introduction to Statistics

Frequency Distributions

Central Tendency

Variability

Z-Scores

Probability

The Distribution of Sample Means

Introduction to Hypothesis Testing

Introduction to the T Statistic

The T Test for Two Independent Samples

The T Test for Two Related Samples

Introduction to Analysis of Variance

Repeated-Measures Anova

Two-Factor Analysis of Variance

Introduction to Regression

Chi-Square Tests

The Binomial Test

Choosing the Right Statistics

Filters

A researcher obtains SS_X = 20, SS_Y = 5, and SP = 7 for a set of n = 25 pairs of scores.The Pearson correlation for these scores is r = 7/10 = 0.70.

The Pearson and the Spearman correlations are both computed for the same set of data.If the Spearman correlation is r_S = +1.00, then what can you conclude about the Pearson correlation?

A set of n = 15 pairs of scores (X and Y values) has SS_X = 4, SS_Y = 25, and SP = 6.The Pearson correlation for these data is