Returns the inverse of the gamma cumulative distribution. If p = GAMMADIST(x,...), then GAMMAINV(p,...) = x.
You can use this function to study a variable whose distribution may be skewed.
Syntax
GAMMAINV(probability,alpha,beta)
Probability is the probability associated with the gamma distribution.
Alpha is a parameter to the distribution.
Beta is a parameter to the distribution. If beta = 1, GAMMAINV returns the standard gamma distribution.
Remarks
-
If any argument is nonnumeric, GAMMAINV returns the #VALUE! error value.
-
If probability < 0 or probability > 1, GAMMAINV returns the #NUM! error value.
-
If alpha ≤ 0 or if beta ≤ 0, GAMMAINV returns the #NUM! error value.
GAMMAINV uses an iterative technique for calculating the function. Given a probability value, GAMMAINV iterates until the result is accurate to within ±3x10^-7. If GAMMAINV does not converge after 100 iterations, the function returns the #N/A error value.
Example
|
Probability |
Alpha |
Beta |
Formula |
Description (Result) |
|
0.068094 |
9 |
2 |
=GAMMAINV([Probability],[Alpha],[Beta]) |
Inverse of the gamma cumulative distribution for the arguments (10) |
