The GAMMADIST function calculates the gamma distribution. It is used when working with variables that may have a skewed distribution. x is the value at which the function is to be evaluated; alpha and beta are parameters to the function. The formula for the gamma distribution is:
and for the standard gamma distribution, that is when b = 1, is:
For example:
GAMMADIST(15, 7, 4)
returns 0.022709.
See also: