1) Using the Work break structure provided below, calculate the expected task times, perform CPM, and compute the standard deviation of project time.

2) Given expected project completion time of 10 months (1.5 months std. dev.), when should we start the project to be 80% confident of on-time completion?

\begin{tabular}{|c|c|c|c|c|} \hline Task & Predecessor & Most likely & Optimistic & Pessimistic \\ \hline A & & 3 days & 2 & 4 \\ \hline B & A & 10 days & 8 & 18 \\ \hline C & A & 5 days & 3 & 10 \\ \hline D & B & 3 days & 3 & 6 \\ \hline E & B,C & 15 days & 13 & 17 \\ \hline F & D & 8 days & 4 & 10 \\ \hline \end{tabular}