The expected project completion time for the construction of a pleasure yatch is 21 months and the project variance is 6. What is the probability that the project will
a. require at least 17 months?
b. be completed in 20 months?
c. require at least 23 months?
d. be completed within 25 months?
Please show the steps . Can you explain how to use the NORMDIST in excel
How do you get the standard deviation?