Finding probability of number of Outrages

Question

In Islamabad city the mean number of power outages is 4 per month. Find the probability that in a given month, a. There are exactly 3 outages b. There are more than 2 outages.

Answer 1

The number of power outages follows a Poisson Distribution. P(x,mu), where x = number of outages and mu equals mean number of outages = e^-mu * mu^x/x!.

mu = 4. For part a), x = 3. For part b) x = 3 and 4, then add probabilities together.