50. Refer to Exercise 21 in which x  available travel space in feet and y  separation distance in feet between a bicycle and a passing car.

a. MINITAB gives and 

.360. Explain why one is much larger than the other.

b. Calculate a 95% CI for expected separation distance when available travel space is 15 feet. (Use

.)

c. Calculate a 95% PI for a single instance of separation distance when available travel space is 20 feet. (Use s .)