# Poisson Command

From GeoGebra Manual

- Poisson[ <Mean> ]
- Returns a bar graph of a Poisson distribution with given mean
*λ*. - Poisson[ <Mean>, <Boolean Cumulative> ]
- Returns a bar graph of a Poisson distribution when
*Cumulative = false*. - Returns a graph of a cumulative Poisson distribution when
*Cumulative = true*. - The first parameter is same as above.
- Poisson[ <Mean>, <Variable Value v>, <Boolean Cumulative> ]
- Let X be a Poisson random variable.
- Returns P( X =
*v*) when*Cumulative*= false. - Returns P( X ≤
*v*) when*Cumulative*= true. - First parameter is same as above.

## CAS Syntax

- Poisson[ <Mean>, <Variable Value v>, <Boolean Cumulative> ]
- Let X be a Poisson random variable.
- Returns P( X =
*v*) when*Cumulative*= false. - Returns P( X ≤
*v*) when*Cumulative*= true. - First parameter is same as above.

**Examples:**`Poisson[3, 1, true]`

yields*\frac{4}{e³}*.`Poisson[3, 1, false]`

yields*\frac{3}{e³}*.