We are given that 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.
Answer: Since the sample size is large enough to consider its distribution to be normal. Therefore, according to central limit theorem the distribution of sample mean is approximately normal with mean and standard deviation given: