Solve the double inequality -tα/2,n-2 α/2,n-2 with t given by the formula of Exercise 25 so that the middle term is y0 and the two limits can be calculated without knowledge of y0. Note that although the resulting double inequality may be interpreted like a confidence interval, it is not designed to estimate a parameter; instead, it provides limits of prediction for a future observation of Y that corresponds to the (given or observed) value x0
Exercise 25
Use the results of Exercises 20 and 21 and the fact that
is a random variable having a normal distribution with zero mean and the variance
Exercises 20
Under the assumptions of normal regression analysis, show that
(a) the least squares estimate of α in Theorem 2 can be written in the form
(b) 
has a normal distribution with
Theorem 2
Exercises 21
This question has been intentionally omitted for this edition.