# Poisson

#### yonerflash

##### New Member
The number of pacients that get into the hospital is 36 per day. Wich is the probability that in one hour 4 pacients get in.

#### TheEcologist

##### Global Moderator
Hi, yonerflash! :welcome: We are glad that you posted here! This looks like a homework question though. Our homework help policy can be found here. We mainly just want to see what you have tried so far and that you have put some effort into the problem. I would also suggest checking out this thread for some guidelines on smart posting behavior that can help you get answers that are better much more quickly.

#### yonerflash

##### New Member
I dont know how to calculate lambda. I know is a Poisson problem
Lambda is 36 / 4 = 9 ?

#### Rhodo

##### New Member
36 are expected in 24 hours, so 36/24 = 1.5 would be expected in a single hour.

#### yonerflash

##### New Member
So lambda is 1.5 and the 4 - 1 proportion doesnt change it?
So the solution would be
= (e^-1.5 * 1.5^4) / 4!