1. ## poisson distribution

Having trouble with this one:

The customer service counter at the bank has a mean of 5 customers arriving in a given hour, and the number of customers arrviing in an hour is known to be distributed as a poisson random variable

a) what is the probability that the time between customers arriving is greater than a half hour
b)what is the prob that the time btwn customers arriving is between 15 and 45 minutes

Thanks for any help

2. Originally Posted by limbo586
Having trouble with this one:

The customer service counter at the bank has a mean of 5 customers arriving in a given hour, and the number of customers arrviing in an hour is known to be distributed as a poisson random variable

a) what is the probability that the time between customers arriving is greater than a half hour
b)what is the prob that the time btwn customers arriving is between 15 and 45 minutes

Thanks for any help
If thew number of customers arriving per hour has a Poisson distribution with mean $\mu$, then the intervals between arrivals has an exponential distribution with mean time between arrivals of $1/\mu$ hours.

CB