What is Poisson Distribution

Just like Binomial Distribution, Poisson Distribution is also a random variable distribution. We apply Poisson distribution in any one of the following cases:

1. n, the number of times that the experiment is conducted is sufficiently large.
2. Occurrence of success is rare.
3. Occurrence of success is frequent.

In Poisson distribution, values of random variable are the number of successes.

If λ is a parameter then probability of getting k times success is

Now Poisson distribution with parameter λ can be written in tabular form as follow:

Theorems :-

1. Arithmetic Mean of Poisson variable X whose parameter is λ, is λ
2. Variance of a Poisson variable X with parameter λ, is λ