# How can you recognize a poisson distribution?

##### 1 Answer

Poisson distribution is discrete, has no upper bound, and has a fixed "rate".

#### Explanation:

For example, number hurricanes per year in a particular region.

**discrete** means that the variable can only take countable values.

**no upper bound** separates this from binomial, theoretically speaking, the number hurricanes have no upper bound. If 7 have occurred this year, the 8th could still occur.

**fixed rate** means that the expected number of hurricanes should not change. This expectation is denoted by rate (

Another example:

An important assumption for calculation is that **no two arrivals coincide**. So for example, if you want to model the number of customers entering in a restaurant, no two customers can enter at the same point of time.