You are using the three-point estimating technique to estimate the duration of a schedule activity. Which of the following is the correct formula for calculating variance assuming a triangular distribution?
A. (pessimistic + optimistic + most likely )/3
B. ((optimistic-pessimistic)/6)^2
C. [(optimistic-pessimistic)^2+(most likely-pessimistic)*(most likely-optimistic)]/18
D. (pessimistic +4 *(most likely)+ optimistic)/6