# GAMMAINV

The GAMMAINV function calculates the inverse of the gamma cumulative distribution function for a specified probability and input parameters. This function is commonly used in statistics and probability analysis to determine the input value corresponding to a given probability in a gamma distribution.

## Syntax

=GAMMAINV(`Probability`

, `Alpha`

, `Beta`

)

`Probability` | The probability for which you want to find the input value. |

`Alpha` | The alpha parameter of the gamma distribution. |

`Beta` | The beta parameter of the gamma distribution. |

## About GAMMAINV

When dealing with gamma distributions and the need to uncover the input value associated with a specific probability, turn to GAMMAINV in Excel. It serves as a handy tool for determining the value that corresponds to a given probability in the gamma cumulative distribution function, facilitating precise calculations in statistical analysis and probability studies. To effectively utilize GAMMAINV, you provide the desired probability, along with the alpha and beta parameters that characterize the gamma distribution. By inputting these parameters, you enable Excel to compute the inverse gamma distribution function, enabling you to unravel the input value tied to the specified probability with ease.

## Examples

Suppose you have a gamma distribution with Alpha = 2 and Beta = 1.5. You want to find the input value associated with a probability of 0.75. The GAMMAINV formula would be: =GAMMAINV(0.75, 2, 1.5) This will return the input value corresponding to a probability of 0.75 in the specified gamma distribution.

## Questions

**How does the GAMMAINV function work?**

The GAMMAINV function calculates the inverse of the gamma cumulative distribution function by finding the input value corresponding to a specified probability in a gamma distribution characterized by the alpha and beta parameters.

**Can GAMMAINV handle probabilities outside the range of 0 to 1?**

No, the GAMMAINV function is designed to work with probabilities within the range of 0 to 1. Ensure that the probability value provided falls within this range for accurate results.

**What happens if the alpha or beta parameters are negative in the GAMMAINV function?**

The alpha and beta parameters in the GAMMAINV function must be positive numeric values as they define the shape and scale of the gamma distribution. Providing negative values for these parameters will result in an error.

## Related functions

GAMMADIST

GAMMALN

BETAINV

NORMINV

PERCENTILE