This topic has not yet been rated - Rate this topic

# WorksheetFunction.Gamma_Inv Method (Excel)

Office 2010

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

Version Added: Excel 2010

expression .Gamma_Inv(Arg1, Arg2, Arg3)

expression A variable that represents a WorksheetFunction object.

### Parameters

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

Double

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.