# The Excel CHISQ.INV.RT Function

Related Functions:
CHISQ.DIST.RT
CHISQ.INV
CHISQ.INV.RT and CHISQ.DIST.RT

The Chisq.Inv.Rt function is the inverse of the Excel Chisq.Dist.Rt function.

I.e. for a supplied probability, the Chisq.Inv.Rt function finds the value of x such that:

Chisq.Dist.Rt( x, degrees_freedom ) = probability

## Function Description

The Excel Chisq.Inv.Rt function calculates the inverse of the right-tailed probability of the Chi-Square Distribution.

The function is new in Excel 2010 and so is not available in earlier versions of Excel. However, the Chisq.Inv.Rt function is simply an updated version of the Chiinv function, which is available in earlier versions of Excel.

The syntax of the Chisq.Inv.Rt function is:

CHISQ.INV.RT( probability, degrees_freedom )

Where the function arguments are:

 probability - The probability of the right-tailed chi-square distribution, for which you want to find the value of x. degrees_freedom - The number of degrees of freedom (must be a positive integer).(If the supplied degrees_freedom is a decimal, this is truncated to an integer).

## Chisq.Inv.Rt Function Examples

The spreadsheet below shows five examples of the Excel Chisq.Inv.Rt function, used to calculate the inverse of the right-tailed chi-square distribution for different probability values, and different degrees of freedom.

Formulas:
A
1=CHISQ.INV.RT( 0.5, 1 )
2=CHISQ.INV.RT( 0.75, 1 )
3=CHISQ.INV.RT( 0.1, 2 )
4=CHISQ.INV.RT( 0.8, 2 )
5=CHISQ.INV.RT( 0.25, 3 )
Results:
A
10.454936423
20.101531044
34.605170186
40.446287103
54.108344936

For further examples of the Excel Chisq.Inv.Rt function, see the Microsoft Office website.

## Chisq.Inv.Rt Function Errors

If you get an error from the Excel Chisq.Inv.Rt function this is likely to be one of the following:

Common Errors
 #NUM! - Occurs if either:The supplied probability value is ≤ 0 or > 1;The supplied degrees_freedom argument is <1. #VALUE! - Occurs if any of the supplied arguments is non-numeric.