# Thread: Poisson process problem

1. ## Poisson process problem

I'm struggling with this question.

The solutions are:

a) 0.185
b) 0.761

But I don't know how to get to them. I appreciate your help.

2. ## Re: Poisson process problem

a) $p=P[\text{at least 5 calls}] = 1 - P[\text{4 calls or less}] = 1 - \sum \limits_{k=0}^4 \dfrac{(3)^k e^{-3}}{k!} = 0.184737$

b) using $p$ from part (a) this is just a binomial distribution $n=7, ~p$

$P[\text{at least 1 cell gets 5 calls}] = 1 - P[\text{0 cells get 5 calls}] = 1 - (1-p)^7 = 0.760622$

3. ## Re: Poisson process problem

Thanks a lot!