A small project is composed by 7 activities whose time estimates are listed in the table below. Activities are identified by their beginning (i) and ending (j) node numbers.

Activity (i-j) Estimated optimistic Duration most weekly (weeks) pessimistic 1-2 1 1 7 1-3 1 4 7 1-4 2 2 8 2-5 1 1 1 3-5 2 5 14 4-6 2 5 8 5-6 3 6 15 (a) Draw the project network. (b) Find the expected duration ad variance for each activity. What is the expected project length?

Calculate the variance and standard deviation of the project length what is probability that the project will completed? (i) At least 4 weeks earlier than expected time. (ii) No more than 4 weeks later than expected time.