# GammaInv Script and chart function

`GammaInv()` returns the inverse of the accumulated probability of the Gamma distribution.

Syntax:

GammaInv(prob, k, θ)

Return data type: number

Arguments

| Argument | Description |
| --- | --- |
| `prob` | A probability associated with the Gamma-probability distribution. It must be a number between 0 and 1. |
| `k` | A positive number defining the shape parameter. |
| `θ` | A positive number defining the scale parameter. |

This function is related to the `GammaDist` function in the following way:   
`If prob = GammaDist(value, k, θ), then GammaInv(prob, k, θ) = value`