PsiPert (a,c,b,...)
PsiPert (a,c,b) is a form of the Beta distribution, often used to estimate project completion times in the Program Evaluation and Review Technique, where a is the minimum time, b is the maximum time, and c is the most likely time. These parameters are used to compute the shape parameters α1,α2 used in the PsiBeta function, as shown below.
Alternate Formulation: PsiPertAlt
PsiPertAlt is the PsiPert distribution defined through alternative arguments. Three parameters are required which must be chosen from the following list: 3 different percentiles, mean, var, min, likely or max.
