conceptual regression analysis

If the correlation between X and Y is zero, the best predictor of the value of Y is the mean of X.

• false

In a linear regression analysis, the higher the Pearson's r, the lower the values of the residuals

• True

In addition to an interval-ratio level predictor, a nominal predictor can also be used in linear regression analysis

In linear regression analysis, if the slope is +.50, which of the following is true?

A. you can predict 25% of the variance in Y from the value of X.

B. you can predict 50% of the variance in Y from the value of X

C. for every unit decrease in X there will be a 1/2 unit increase in Y.

D. None of the above are true.

In linear regression, if the slope is -.25, which of the following is true

• Every unit increase in X will result in a 1/4 unit decrease in Y

In linear regression, the change in value of Y that occurs with each unit change in X is referred to as the

• slope

In linear regression, the intercept is the value of X when the value of Y is 0

• false

In linear regression, the mean value of all residuals will be greater for a correlation of -.70 than for a correlation of +.60

• false

In linear regression analysis, the intercept is determined by what factors?

a. the mean of Y

B. the mean of X

C. the slope of the regression line 

D. all of the above

 The regression line represents the line that

A. minimizes the residuals when using the value of X to predict the value of Y

B. intersects the Y axis at the point where the X variable equals 0

C. slopes downward when the correlation between X and Y is negative

D. all of the above

The slope of the regression line is determined by

A. the sign of Pearson's r for X and Y

B. The absolute value of Pearson's r for X and Y

C. The standard deviation of both X and Y

D. All of the above

When all of the points in a scatterplot lie on the regression line, the correlation between the two variables must be

• + 1.0 or - 1.0

In a case where two predictors are both significantly correlated with the criterion, but where the multiple R is NOT significant, what should one do?

• perform simple linear regression with the one predictor that has the highest Pearson r with the criterionGo back and check your work because the value of R cannot be correct

The larger the multiple R the ___________ from __________ on average will be the predicted values of Y (the criterion)

• farther from; the mean of Y

The lower the multiple R, the ___________  the ____________  will be each point in the 3-dimensional scatter plot.

• farther from; regression plane

As the correlation between the two predictor variables increases, what will happen to the value of multiple R?

• It will decrease