35.

(a) Using PERT, a manager was able to determine that the expected project completion time for the construction of a pleasure yatch is 21 months and the variance is 4 months2?

(i) What is the probability that the project will be completed in over 22 months?

(ii) What is the probability that the project will be completed in the 24th month?

(b) Given the following information:

(i) Draw the project network. Obtain the standard deviation of completion time of each activity.
(ii) Calculate expected duration of the project and its standard deviation.

(iii) Find the probability that the project will be completed in 38 weeks.
(iv) If the project manager wants to be 90 per cent sure that the project should be completed in time, how many weeks prior to the deadline should he start it?

Activity Nodes Optimistic Time Estimates (weeks) Pessimistic Expected A 1-2 3 15 8 BCD 1-3 4 8 6 1-4 6 20 2-4 6 26 12 6 E 2-6 5 9 7 F 3-4 G 3-5 H 4-7 10 I 5-7 J 5-8 10 K 6-7 10 L 7-8 5228986 6404002 15 12 96 12 11 6 10 10 18 14 3