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. What is the expected number of calls in one hour? What is the probability of three calls in five minutes (to 4 decimals)?

Answer 1

Answer: N= 30 calls in 1 hour

P(3)= 0.2138

Explanation:

Calls come in at the rate of 1 /2mins

Rate = 0.5/mins

Number of Expected calls in 1 hour= 60mins; is given by,

N= rate × time

N= 0.5/mins × 60mins

N= 30 calls

Using poisson distribution

Mean of calls in 5 mins = 5min( 0.5/min)= 2.5

P(3) = e^-2.5 × 2.5^3/3!

P(3) = 0.2138