Using PERT, Adam Munson 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 $9.$

a$)$ The probability that the project will be completed in $12$ months $=0\mathrm{.}0013($round your response to four

decimal places$).$

b$)$ The probability that the project will be completed in $20$ months $=0\mathrm{.}3694($round your response to four

decimal places$).$

c$)$ The probability that the project will be completed in $24$ months $=0\mathrm{.}8413($round your response to four

decimal places$).$

d$)$ The probability that the project will be completed in $30$ months $=$

$($round your response to four decimal places$).$