Using the regression from Exercise 12-2,

(a) Find a 95% confidence interval for the coefficient of hourly 1 test.

(b) Find a 95% confidence interval for the mean final grade for students who score 80 on the first test and 85 on the second. 

(c) Find a 95% prediction interval for a student with the same grades as in part (b).

Exercise 12-2

A class of 63 students has two hourly exams and a final exam. How well do the two hourly exams predict performance on the final?

The following are some quantities of interest:

Transcribed Image Text:

0.9129168 (X'X) =-0.00981502 -0.00071123 -9.815022e-03 1.49724le- 04 -4.158056e- 05 -7.11238e-04 -4.15806e- 05 5.81235e-05 4871.0 (X'y) =| 426011.0 367576.5