Use the results of Problem 16 in Section 14.1 to answer the following questions:

(a) Predict the mean nicotine content of all cigarettes whose tar content is 12 mg.

(b) Construct a 95% confidence interval for the tar content found in part (a).

(c) Predict the nicotine content of a randomly selected cigarette whose tar content is 12 mg.

(d) Construct a 95% prediction interval for the nicotine content found in part (c).

(e) Explain why the predicted nicotine contents found in parts (a) and (c) are the same, yet the intervals constructed in parts (b) and (d) are different.