Question

During the period of time that a local university takes phone-in registrations, calls come in at the rate of one every two minutes.

1. What is the expected number of calls in one hour?
2. What is the probability of three calls in five minutes (to 4 decimals)?
3. What is the probability of no calls in a five-minute period (to 4 decimals)?

Answer 1

30, 0.2138,0.0821

Explanation:

Given that during the period of time that a local university takes phone-in registrations, calls come in at the rate of one every two minutes.

Hence in one hour expected calls = 60/2 = 30

1) the expected number of calls in one hour=30

2) the probability of three calls in five minutes

In 5 minutes average is 2.5

This is a Poisson process

P(X=3) = 0.2138

3) the probability of no calls in a five-minute period

= P(X=0) = 0.0821