An efficiency expert wants to determine whether the time an assembly worker requires to perform a standard task might be related to (1) the number of years on the job and (2) the score on a pre-employment aptitude test. The following data have been collected.
y 5 Time, seconds: 52 48 56 52 48 45 42
|
x1 5 Years on job:
|
7
|
14
|
8
|
6
|
10
|
6 10
|
|
x2 5 Test score:
|
73
|
78
|
71
|
75
|
78
|
78 80
|
|
y 5 Time, seconds:
|
51
|
51
|
53
|
47
|
45
|
49
|
|
x1 5 Years on job:
|
11
|
10
|
6
|
8
|
12
|
12
|
|
x2 5 Test score:
|
72
|
79
|
77
|
79
|
84
|
72
|
a. Determine the multiple regression equation and interpret the partial regression coefficients.
b. Determine the 95% confidence interval for the population partial regression coefficients, f31 and f32.
c. Interpret the coefficient of determination and the result of each significance test done by the computer.
d. Analyze the residuals. Does the analysis support the applicability of the multiple regression model to these data?