WorksheetFunction.Gamma_Inv method (Excel)

Returns the inverse of the gamma cumulative distribution. If p = GAMMA_DIST(x,...), then GAMMA_INV(p,...) = x.


expression.Gamma_Inv (Arg1, Arg2, Arg3)

expression A variable that represents a WorksheetFunction object.


Name Required/Optional Data type Description
Arg1 Required Double Probability - the probability associated with the gamma distribution.
Arg2 Required Double Alpha - a parameter to the distribution.
Arg3 Required Double Beta - a parameter to the distribution. If beta = 1, Gamma_Inv returns the standard gamma distribution.

Return value



You can use this function to study a variable whose distribution may be skewed.

If any argument is text, Gamma_Inv returns the #VALUE! error value.

If probability < 0 or probability > 1, Gamma_Inv returns the #NUM! error value.

If alpha ≤ 0 or if beta ≤ 0, Gamma_Inv returns the #NUM! error value.

Given a value for probability, Gamma_Inv seeks that value x such that GAMMA_DIST(x, alpha, beta, TRUE) = probability. Thus, precision of Gamma_Inv depends on precision of Gamma_Dist. Gamma_Inv uses an iterative search technique. If the search has not converged after 100 iterations, the function returns the #N/A error value.

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