試題詳解

159. The number of traffic accidents per week at intersection Q has a Poisson distribution with mean 3. The number of traffic accidents per week at intersection R has a Poisson distribution with mean 1.5.

Let A be the probability that the number of accidents at intersection Q exceeds its mean.
Let B be the corresponding probability for intersection R.

Calculate B – A.
(A) 0.00
(B) 0.09
(C) 0.13
(D) 0.19
(E) 0.31