general statistics

Question

The number of traffic accidents per week in a small city has a Poisson distribution with mean equal to 3.

What is the probability of at least one accident in 2 weeks?

A. 0.0025

B. 0.0174

C. 0.1991

D. 0.9975

Answer 1

The probability of zero accidents in one week is equal to:

e^-3 * (3)^0/0! = 0.05

So the probability of zero accidents in two weeks is: 0.05 * 0.05 = 0.0025

Thus the probability of at least 1 accident in two weeks = 1 - 0.0025 = 0.9975.