Consider the data and simple linear regression in Exercise 6-4.
(a) Find the mean turbidity given that the temperature is 25.0 degrees.
(b) Compute a 95% CI on this mean response.
(c) Compute a 95% PI on a future observation when temperature is equal to 25.0 degrees.
(d) What do you notice about the relative size of these two intervals? Which is wider and why?