Consider the NFL data in Exercise 12-4. (a) Find a 95% confidence interval on B8. (b) What is the estimated standard error of when x2 = 2000 yards, x7 = 60%, and x8 = 1800 yards? (c) Find a 95%...

Consider the NFL data in Exercise 12-4.
(a) Find a 95% confidence interval on B8.
(b) What is the estimated standard error of when x2 = 2000 yards, x7 = 60%, and x8 = 1800 yards?
(c) Find a 95% confidence interval on the mean number of games won when x2 = 2000, x7 = 60, and x8 = 1800.