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.

a) P(x=3)=(λ^xe^-λ)/x!=(4³e^-4)/3!=0.195

b)P(x>2)=1-P(x=0)-P(x=1)-P(x=2)=1-(4⁰e^-4)/0!-(4¹e^-4)/1!-(4²e^-4)/2!=1-0.0183-0.07326-0.1465=0.76194