CHIINV ( probability , degrees-freedom )

Description: Computes the inverse of the one-tailed probability of the chi-squared distribution. Given a value for probability, CHIINV seeks for a value x such that CHIDIST(x, degrees-freedom) = probability. Thus, precision of CHIINV depends on precision of CHIDIST. CHIINV uses an iterative search technique.

Arguments:

Name	Type	Description
probability	number	A probability associated with the chi-squared distribution.
degrees-freedom	number	The number of degrees of freedom, truncated to an integer.

Return Type and Value: number – The inverse of the one-tailed probability of the chi-squared distribution.

However, if

• probability < 0 or probability > 1, #NUM! is returned.

• degrees-freedom < 1 or degrees-freedom ≥ 1010, #NUM! is returned.

• The search has not converged after some implementation-defined number of iterations, #N/A is returned

[Example:

CHIINV(0.5,4) results in 3.356694001
CHIINV(0.3,7) results in 8.38343064

end example]