Sunita's job is to provide technical support to computer users.Suppose the arrival of calls can be modeled by a Poisson distribution with a mean of 4.9 calls per hour.What is the probability that in the next 30 minutes there will be 2 or more calls?
A)0.7886
B)0.2590
C)0.0894
D)0.7023
E)0.9561

Question

Quizplus · Accepted Answer

To solve this problem, we need to first convert the mean from per hour to per 30 minutes.

4.9 calls per hour = 2.45 calls per 30 minutes

Next, we can use the Poisson distribution formula:

P(X ≥ 2) = 1 - P(X = 0) - P(X = 1)

= 1 - (e^-2.45)(2.45^0/0!) - (e^-2.45)(2.45^1/1!)

= 1 - 0.0827 - 0.2020

= 0.7153

Therefore, the probability of there being 2 or more calls in the next 30 minutes is 0.7153, which is closest to Choice D (0.7023).

Sunita's Job Is to Provide Technical Support to Computer Users