Question 1

Because r indicates the degrees to which variation in one variable is related to variation in another, it can also be expressed in terms of the decomposition of the total variation.

Accepted Answer

A) True 
 B)False

Question 2

The product moment correlation helps us determine the strength of the association between two metric variables. Regression analysis helps us determine which variables cause a change in other variables.

Accepted Answer

A) True 
 B)False

Question 3

The hypotheses for the test for significance of the coefficient of determination are: H0: R2pop  = 0 ; H1: R2pop  > 0.

Accepted Answer

A) True 
 B)False

Question 4

The vertical distance from a point to the regression line is the squared error, e2.

Accepted Answer

A) True 
 B)False

Question 5

If the nonmetric variables are nominal and numeric, Spearman's rho and Kendall's tau are two measures of nonmetric correlation that can be used to examine the correlation between them.

Accepted Answer

A) True 
 B)False

Question 6

A residual is the difference between the observed value of Yi and the value predicted by the regression equation, Ŷi.

Accepted Answer

A) True 
 B)False

Question 7

Which statement is not true about the constant b in the bivariate regression equation Ŷ i = a + bXi?

Accepted Answer

A) It is usually referred to as the non-standardized regression coefficient. 
B) It is the slope of the regression line and it indicates the expected change in Y when X is changed by one unit. 
C) It is the intercept of the regression line and it indicates the value of Y when X is zero. 
D) It may be computed as b=COVxy/Sx2.

Question 8

The equation for r involves dividing the ________ by ________.

Accepted Answer

A) COVxy; the product of the variance of X and Y (Sx2Sy2) 
B) product of the standard deviation of X and Y (SxSy); COVxy  
C) COVxy; the product of the standard deviation of X and Y (SxSy) 
D) product of the variances of X and Y (Sx2Sy2); COVxy

Question 9

________ is a regression procedure in which the predictor variables enter or leave the regression equation one at a time.

Accepted Answer

A) Multiple regression 
B) Bivariate regression 
C) Dummy variable regression 
D) Stepwise regression

Question 10

The product moment correlation, r, is the most widely used statistic summarizing the strength of association between two metric (interval or ordinal scaled)variable, say X and Y.

Accepted Answer

A) True 
 B)False

Question 11

The formula for the coefficient of determination is r2 = SSreg/ SSy.

Accepted Answer

A) True 
 B)False

Question 12

What are the assumptions made by the regression model in estimating the parameters and in significance testing?

Accepted Answer

The answer of What are the assumptions made by the...

Question 13

The ________ is a measure of the association between two variables after controlling or adjusting for the effects of one or more additional variables.

Accepted Answer

A) regression analysis 
B) partial correlation coefficient 
C) ANOVA 
D) product moment correlation

Question 14

Which statement is not true about partial regression coefficients?

Accepted Answer

A) The combined effects of X1 and X2 on Y are additive. In other words, if X1 and X2 are each changed by one unit, the expected change in Y would be (b1 + b2). 
B) The beta coefficients are the partial regression coefficients obtained when all the variables (Y, X1, X2...Xk) have been standardized to a mean of 0 and a variance of 1 before estimating the regression equation. 
C) Partial regression coefficients have an order associated with them. 
D) Both A and B are not true.

Question 15

In multiple regression, if the overall null hypothesis is rejected, we know which specific coefficients (βis)are nonzero.

Accepted Answer

A) True 
 B)False

Question 16

In bivariate regression, the null hypothesis is that no linear relationship exists between X and Y, or H0: β1 = 0.

Accepted Answer

A) True 
 B)False

Question 17

The term beta coefficient or beta weight is used to denote the standardized regression coefficient.

Accepted Answer

A) True 
 B)False

Question 18

When considering nonmetric correlation, as a rule of thumb, ________ is to be preferred when a large number of cases fall into a relatively small number of categories (thereby leading to a large number of ties).

Accepted Answer

A) Spearman's rho 
B) Kendall's tau 
C) chi-square 
D) Pearson product moment correlation

Question 19

The correlation coefficient between two variables varies depending on their underlying units of measurement.

Accepted Answer

A) True 
 B)False

Question 20

Regression analysis is concerned with the nature and degree of association between variables and does not imply or assume any causality.

Accepted Answer

A) True 
 B)False

Exam 17: Correlation and Regression

Because r indicates the degrees to which variation in one variable is related to variation in another, it can also be expressed in terms of the decomposition of the total variation.

The product moment correlation helps us determine the strength of the association between two metric variables. Regression analysis helps us determine which variables cause a change in other variables.

The hypotheses for the test for significance of the coefficient of determination are: H₀: R²_pop= 0 ; H₁: R²_pop> 0.

The vertical distance from a point to the regression line is the squared error, e²^.

If the nonmetric variables are nominal and numeric, Spearman's rho and Kendall's tau are two measures of nonmetric correlation that can be used to examine the correlation between them.

A residual is the difference between the observed value of Y_i and the value predicted by the regression equation, Ŷ_i.

Which statement is not true about the constant b in the bivariate regression equation Ŷ_i= a + bX_i?

The equation for r involves dividing the by .

________ is a regression procedure in which the predictor variables enter or leave the regression equation one at a time.

The product moment correlation, r, is the most widely used statistic summarizing the strength of association between two metric (interval or ordinal scaled)variable, say X and Y.

The formula for the coefficient of determination is r² = SS_reg/ SS_y.

What are the assumptions made by the regression model in estimating the parameters and in significance testing?

The ________ is a measure of the association between two variables after controlling or adjusting for the effects of one or more additional variables.

Which statement is not true about partial regression coefficients?

In multiple regression, if the overall null hypothesis is rejected, we know which specific coefficients (β_is)are nonzero.

In bivariate regression, the null hypothesis is that no linear relationship exists between X and Y, or H₀: β₁=0.

The term beta coefficient or beta weight is used to denote the standardized regression coefficient.

When considering nonmetric correlation, as a rule of thumb, ________ is to be preferred when a large number of cases fall into a relatively small number of categories (thereby leading to a large number of ties) .

The correlation coefficient between two variables varies depending on their underlying units of measurement.

Regression analysis is concerned with the nature and degree of association between variables and does not imply or assume any causality.