Two intervals are given, A and B, for the same value of the explanatory variable.

A: 15.1 to 23.9 ;

B: 17.4 to 21.6 ;

(a) Which interval is the confidence interval for the mean response? A or B?

Which interval is the prediction interval for the response? A or B? (b) What is the predicted value of the response variable for this value of the explanatory variable? Enter the exact answer. The predicted value is ______________