Explain briefly and distinguish solution for parts a,b,c,d

Suppose the service time, in minutes, at a bank has the Exponential distribution with = 1/2 . Use the central limit theorem to estimate the probability that the average service time of the first n customers is less than 2.5 minutes, when:

a) n=16.

b) n=36.

c) n = 100.

d) What happens when n increases? Explain briefly why.