Exam 14: Correlation and Regression

It is possible for the regression equation to have none of the actual (observed)data points located on the regression line.

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

The effect size for the data from an independent-measures t test can be measured by r²,which is the percentage of variance accounted for.Which of the following also produces the value for r²?

For the linear equation Y = 2X - 3,which of the following points will not be on the line?

An analysis of regression is used to test the significance of a linear regression equation based on a sample of n = 20 individuals.What are the df values for the F-ratio?

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.

A set of X and Y scores has SS_X = 10,SS_Y = 36,and SP = 20.The regression equation for these scores will have a slope constant of 2.

The sign of the correlation (+/)is generally meaningless for the point-biserial correlation and the phi-coefficient.

If the value of the Pearson correlation is r = +1.00 or 1.00,then all data points in a scatter plot fit perfectly on a straight line.

A researcher measures driving distance from college and weekly cost of gas for a group of commuting college students.What kind of correlation is likely to be obtained for these two variables?

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.

If the Pearson correlation between X and Y is r = 0.60,then the regression equation predicts 36% of the variance in the Y scores.

If the Pearson correlation for a set of scores is equal to +1.00,then the Spearman correlation for the same scores would also be equal to +1.00.

The Pearson correlation is calculated for a sample of n = 20 individuals.If a hypothesis test is used to determine whether the correlation is significant,what df value would be used for the t statistic?

For the regression equation Y = 2X - 3,if the mean for X is M_X = 5,what is the mean for Y?

The scatter plot for a set of X and Y values shows the data points clustered in a nearly perfect circle.For these data,what is the most likely value for the Pearson correlation?

The line produced by the equation Y = 4X - 5 crosses the vertical axis at Y = 5.

For a regression equation with a slope of b = 3,if M_X = 3 and M_Y = 10,then the Y-intercept for the equation is 1.

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

A set of n = 25 pairs of scores (X and Y values)has a Pearson correlation of r = 0.80.How much of the variance for the Y scores is predicted by the relationship with X?