THREE TWO Please show ALL your work and EXPLAIN your answer. Help with the incomplete questions PART D ONLY

Using PERT, Adam Munson was able to determine that the expected project completion time for the construction of a pleasure yacht is 24 months, and the project variance is 4. a) The probability that the project will be completed in 20 months = 0.0228 (round your response to four decimal places). b) The probability that the project will be completed in 23 months = 0.3085 (round your response to four decimal places). c) The probability that the project will be completed in 26 months = 0.8413 (round your response to four decimal places). d) The probability that the project will be completed in 28 months = (round your response to four decimal places)