# Poisson Distribution: finding the MEan

1. Oct 29, 2009

### Niall101

A store opens at 8 in the morning. from 8 until 10 customers arrive at poisson rate 6 per hour. Between 10 and 12 they arrive at a poisson rate of 10 per hour. From 12 to 2, the store closes for lunch, Finally from 2 to 5 the arrival rate drops linearly from 10 per hour at 2 to four per hour at 5. Determin the mean number of customers that enter the store on a given day.

Firstly Im not sure what to do here except maybe from 2 to 5 we can say the Mean rate is 7 per hour?

2. Oct 29, 2009

### hamster143

Try a smaller problem first. If the store is open for two hours, from 8 to 10, and customers arrive at poisson rate 6 per hour, can you calculate (or at least guess) the mean number of customers that arrive during these two hours?

3. Oct 29, 2009

### Niall101

Hi I assume it would be 12. 2 x 6?

I have an answer for this question now. I just took the mean per hour and for the last 3 hours took the mean to be 7 and I got 53. It just seams too easy. Its the last question on a problem sheet and the first 5 were much more difficult and more involved.