Consider the stack loss data in Exercise 12-16.

(a) Calculate 95% confidence intervals on each regression coefficient.

(b) Calculate a 95% confidence interval on mean stack loss when and

(c) Calculate a prediction interval on stack loss for the same values of the regressors used in the previous part.

(d) Calculate a 95% confidence interval and a 95% prediction interval on stack loss when , and Compare the widths of these intervals to those calculated in parts

(b) and (c). Explain any differences in widths.