mail order company receives a steady supply of orders by telephone. The manager records the

number of calls received per day over a period of 3 months and found that it can be modeled via

Poisson distribution with mean 8 orders per week (note: They only work 5 days in a week).

a)

What is the probability that the company will receives 30 orders by telephone in a month?

(hint: Use appropriate approximation)

(8 marks)

What is the probability that the company need to wait at most 3 days to receives an order

over the phone?

(7 marks)

c)

What is the probability that the company needs to wait for at least 2 days to receives 3

orders by telephone?