# mathematics

1. In regression analysis, the residuals represent the:

A. difference between the actual y values and their predicted values

B. difference between the actual x values and their predicted values

C. square root of the coefficient of determination

D. change in y per unit change in x

2.In the simple linear regression model, the slope represents the:

A. value of x when y = 0

B. change in y per unit change in x

C. change in x per unit change in y

D. value of y when x = 0

3.The coefficient of determination R2 measures the amount of:

A. variation in y that is unexplained by variation in x

B. variation in x that is unexplained by variation in y

C. variation in y that is explained by variation in x

D. variation in x that is explained by variation in y

4.If we are interested in determining whether two variables are linearly related, it is necessary to:

A. perform the t-test of the coefficient of correlation ρ

B. perform the t-test of the slope β1

C. either A or B since they are identical

D. calculate the regression standard error s

5.Which of the following statistics and procedures can be used to determine whether a linear model should be employed?

A. The standard error of estimate

B. The t-test of the slope

C.The coefficient of determination

D. All of the above answers are correct

6.The regression standard error s is given by:

A. SSE/(n−2)

B. √SSE/(n−2)

C. (√SSE/(n−2)) (whole thing is under √)

D. SSE/√n−2

7.The symbol for the sample coefficient of correlation is:

B. ρ

C. ρ2

D. r2

8. Given the least squares regression line yˆ=−2.48+1.63x, and a coefficient of determination of 0.81, the coefficient of correlation is:

A. -0.85

B. 0.90

C. 0.85

D. -0.90