So my question is: Assume the number of customers calling customer service is Poisson distributed, with an average rate of $10$ customers per minute. What is the probability that no one calls in a one-minute period?
So I've defined my random variable as $X$ representing the number of customers that call in the next minute. $X \sim Poisson(\lambda=10)$. When I plug all these into my poisson distribution formula I get indefinite because zero ends up being the denominator. I'm a little confused so I would love some help! Thanks
Poisson pmf is of the form of $$\exp(-\lambda) \frac{\lambda^x}{x!}$$
Notice that $0!=1$.