1. This is a small set of data provided to investigate the relationship between the age of a lab computer and the number of service calls on it for the school year. Minitab output for these data follows. The following data was reported: X Age of lab computer 1 1 2 2 2 3 3 3 3 4 5 5
Y Number of repair calls 1 0 2 0 3 1 3 2 5 3 5 4
The regression equation is
rep call = - 0.297 + 0.958 age
Predictor Coef SE Coef T P
Constant -0.2966 0.8553 -0.35 0.736
age 0.9576 0.2751 3.48 0.006
S = 1.21989 R-Sq = 54.8% R-Sq(adj) = 50.3%
Analysis of Variance Source DF SS MS F P
Regression 1 18.035 18.035 12.12 0.006
Residual Error 10 14.881 1.488
Total 11 32.917
What is the coefficient of determination for this relationship?
a. 54.8%.
b. 50.3%.
c. 1.220.
d. -.2966
2. This is a small set of data provided to investigate the relationship between the age of a lab computer and the number of service calls on it for the school year. Minitab output for these data follows. The following data was reported:
X Age of lab computer 1 1 2 2 2 3 3 3 3 4 5 5
Y Number of repair calls 1 0 2 0 3 1 3 2 5 3 5 4
The regression equation is
rep call = - 0.297 + 0.958 age
Predictor Coef SE Coef T P
Constant -0.2966 0.8553 -0.35 0.736
age 0.9576 0.2751 3.48 0.006
S = 1.21989 R-Sq = 54.8% R-Sq(adj) = 50.3%
Analysis of Variance
Source DF SS MS F P
Regression 1 18.035 18.035 12.12 0.006
Residual Error 10 14.881 1.488
Total 11 32.917
Explain what the 95% C. I. (Minitab output below) for x=3 means.
Obs Fit SE Fit 95% CI 95% PI
1 2.576 0.355 (1.785, 3.368) (-0.255, 5.407)
95% C. I for the number of service calls for one particular 3 year old computer.
95% C. I. for the mean number of service calls for computers that are 3 years old.
95% C. I. for the number of service calls for computers that are 3 years old.