Poisson Distribution

Definition:

In statistics, poisson distribution is one of the discrete probability distribution. This distribution is used for calculating the possibilities for an event with the given average rate of value(λ). A poisson random variable(x) refers to the number of success in a poisson experiment.

Example:

Consider, in an office 2 customers arrived today. Calculate the possibilities for exactly 3 customers to be arrived on tomorrow.

Step 1:

Find e^-λ. where, λ=2 and e=2.718 e^-λ = (2.718)^-2 = 0.135.

Step 2:

Find λ^x. where, λ=2 and x=3. λ^x = 2³ = 8.

Step 3:

Find f(x). f(x) = e^-λλ^x / x! f(3) = (0.135)(8) / 3! = 0.18. Hence there are 18% possibilities for 3 customers to be arrived on tomorrow.