# Srangeinv

Srangeinv-func

## Definition:

computes the deviate, , associated with the lower tail probability of the distribution of the Studentized range statistic.

The externally Studentized range,, for a sample, is defined as:

Where is an independent estimate of the standard error of the 's.

For a Studentized range statistic the probability integral, , for degrees of freedom and groups, can be written as:

where

For a given probability , the deviate is found as the solution to the equation

## Parameters:

- p (output, double)
- the probability.
- v (input,double)
- the number of degrees of freedom for the experimental error . ≥ 1.0
- ir (input, int)
- the number of groups, .
- q (output, double)
- the Studentized range statistic,.