What is GAMMA.INV function in Excel? GAMMA.INV function is one of Statistical functions in Microsoft Excel that returns the inverse of the gamma cumulative distribution. If p = GAMMA.DIST(x,…), then GAMMA.INV(p,…) = x. You can use this function to study a variable whose distribution may be skewed. Syntax of GAMMA.INV function GAMMA.INV(probability,alpha,beta) The GAMMA.INV function syntax has the following arguments: Probability …