Using PERT, Ed Rose was able to determine that the expected project completion time for the construction of a pleasure yacht is 21 months and the project variance is 4.
(a) What is the probability that the project will be completed in 17 months or less?
(b) What is the probability that the project will be completed in 20 months or less?
(c) What is the probability that the project will be completed in 23 months or less?
(d) What is the probability that the project will be completed in 25 months or less?