A project has four activities (A, B, C, and D) that must be performed sequentially. The probability distributions for the time required to complete each of the activities are as follows. Activity Activity Time (weeks) Probability A 5 0.30 6 0.35 7 0.20 8 0.15 B 3 0.15 5 0.60 7 0.25 C 10 0.10 12 0.25 14 0.35 16 0.25 18 0.05 D 8 0.65 10 0.35 (a) Construct a spreadsheet simulation model to estimate the average length of the project (in weeks) and the standard deviation of the project length. (Use at least 1,000 trials. Round you answers to one decimal place.) average weeks standard deviation weeks (b) What is the estimated probability that the project will be completed in 35 weeks or less