# Documentation/Calc Functions/CHISQ.INV

CHISQ.INV

## Category:

Statistical Analysis

## Summary:

Returns the inverse of the left-tailed probability of the chi-square distribution.

## Syntax:

CHISQ.INV(Probability; DegreesFreedom)

## Returns:

Returns a real number which is the inverse of the left-tailed probability of the chi-square distribution. If p = CHISQ.DIST(x;n;c=1), then CHISQ.INV(p,n) = x. It considers the cumulative probability function for the chi-square distribution.

## Arguments:

Probability.is a real number from 0 to 1 or a reference to the cell containing that number which is the probability value for which the inverse of the chi-square distribution is to be calculated.

DegreesFreedom is a positive integer or a reference to a cell containing that number which is the degrees of freedom for the chi-square function.

• If Probability is greater than 1 or less than 0, then the function returns an error value.
• If DegreesFreedom is less than 1, the function returns an error value.
• If DegreesFreedom is a non-integer numeric value, then the function truncates it to an integer.

For more details on the inverse chi-square distribution, visit Wikipedia

## Examples:

Formula Description Returns
=CHISQ.INV(0.5;1) Inverse of the left-tailed probability of the chi-square distribution for 0.5, using 1 degrees of freedom. Here we can check that =CHISQ.INV(CHISQ.DIST(0.454936423119572;1;1);1) returns 0.454936423119572. 0.454936423119572
=CHISQ.INV(1.2;5) Number greater than 1 so the function returns an error value Err:502
=CHISQ.INV(0.2;0.9) DegreesFreedom less than 1 so the function returns an error value Err:502

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CHISQ.INV