A large pharmaceutical company selected a random sample of new hires and obtained their job performance ratings based on their first six months with the company. These data were used to build a multiple regression model to predict the job performance of new hires based on age and GPA. The results of the analysis are shown below.
Regression Analysis: Job Performance versus Age, GPA
The regression equation is
Job Performance = - 89.7 + 6.18 Age + 2.40 GPA
Predictor Coef SE Coef T P
Constant -89.65 26.29 -3.41 0.002
Age 6.178 1.390 4.45 0.000
GPA 2.395 2.928 0.82 0.420
S = 6.88760 R-Sq = 64.6% R-Sq(adj) = 62.0%

Analysis of Variance
Source DF SS MS F P
Regression 2 2335.4 1167.7 24.62 0.000
Residual Error 27 1280.9 47.4
Total 29 3616.3

1.) At = 0.05 we can conclude that
A)Ageis not a significant variable in predicting job performance.
B)the regression coefficient associated withGPAis significantly different from zero.
C)the regression coefficient associated withAgeis not significantly different from zero.
D)GPAis a significant variable in predicting job performance.
E)Ageis a significant variable in predicting job performance.

2.) How much of the variability in Job Performanceis explained by the regression model?
A)90%
B)64.6%
C)30.33%
D)6.88%
E)This cannot be determined.

3.) Based on the F-statistic and associated P-value, we can conclude at = 0.05 that
A)none of the independent variables in the model are significant.
B)the regression equation is not significant.
C)all independent variables in the model are significant.
D)the regression equation is significant.
E)all independent variables in the model are significant and the regression equation is significant.

4.) Which of the following is the correct interpretation for the regression coefficient ofAge?
A)The regression coefficient is not significantly different from zero.
B)The regression coefficient indicates that the job performance score for an older new hire will, on average, be 6.18 times higher than for a younger new hire.
C)For a new hire with a given GPA, an increase in one year of age is associated with an increase of 6.18 points for job performance on average.
D)The regression coefficient indicates that the job performance score for an older new hire will, on average, be 6.18 times lower than for a younger new hire.
E)For a new hire with a given GPA, an increase in one year of age is associated with a decrease of 6.18 points for job performance on average.