Statistics
posted by Desire Glenn .
From a recent statistical analysis for the last five years, on an average there
are 4 (major) air accidents per month in the world. Let X be the number of air accidents occurred in a randomly selected month. It is known that X ~ Poisson() approximately, where the intensity 4 accidents (monthly average number of accidents). Find the probability that there will be 4 or more air accidents

Sooo...I see you are having problems with this too! LOL

Try the Poisson Distribution.
Poisson distribution (m = mean):
P(x) = e^(m) m^x / x!
Values:
x = 0,1,2,3
m = 4
Calculate P(0), P(1), P(2), P(3). Add together, then subtract that value from 1. This will be your probability.
I hope this will help get you started.