Answer the following questions for the tire problem in Example 8.7.
a. If  = 30,960 and a level α = .01 test is used, what is the decision?
b. If a level .01 test is used, what is β(30,500)?
c. If a level .01 test is used and it is also required that β(30,500) = .05, what sample size n is necessary?
d. If  = 30,960, what is the smallest α at which H0 can be rejected (based on n = 16)?