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:
A. r
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