ACME Fruit Distributing knows that for the last four years, the mean (or average) time it takes a particular truck to make its rounds has been 6.32 hours with standard deviation 0.41 hours. (a)...

ACME Fruit Distributing knows that for the last four years, the mean (or

average) time it takes a particular truck to make its rounds has been 6.32 hours

with standard deviation 0.41 hours.

(a) Suppose you plan to observe this truck 40 times. What is the

approximate distribution of the random sample mean time? Also

specify its parameters.

(b) What is the approximate probability that this random sample mean

(with n=40) will be more than 6.7 hours?

(c) The truck route driver recently retired and Kyle took his place. Would

observing Kyle’s time on one particular day to be 6.1 hours cause you

to think he is certainly a better driver than the previous one? Explain.

(d) Would observing Kyle’s mean (average) time on 40 consecutive days

to be 6.1 hours cause you to think he is certainly a better driver than the

previous one? Explain.