The number of calls coming into a PBX follows a Poisson process with a mean of 120 calls per hour.What is the probability of no calls in a one-minute interval?
A)0
B).1353
C).4060
D).3679

Question

Quizplus · Accepted Answer

We know that the mean number of calls per hour, λ = 120. To find the probability of no calls in a one-minute interval, we need to convert the rate to calls per minute.

λ = 120/60 = 2 calls per minute

The probability of no calls in a one-minute interval is given by the Poisson distribution formula:

P(X = 0) = e^(-λ) * λ^0 / 0!

Substituting the value of λ, we get:

P(X = 0) = e^(-2) * 2^0 / 0! = e^(-2) ≈ 0.1353

Therefore, the correct choice is B, with a probability of approximately 0.1353.

The Number of Calls Coming into a PBX Follows a Poisson