The estimated times and immediate predecessors for the activities in a project at Howard Umrah's retinal scanning company are given in the following table. Assume that the activity times are independent.

This exercise contains only parts $a,b,c,d,$ and $e.$

a$)$ Based on the activity time estimates, the expected times and variance for each of the activities are $($round your response to two decimal places$)$:

b$)$ The expected completion time of the critical path $=19\mathrm{.}79$ weeks $($round your response to two decimal places$).$

The expected completion time of the path other than the critical path $=19\mathrm{.}17$ weeks $($round your response to two decimal places$).$

c$)$ The variance of the critical path $=,$ weeks $($round your response to two decimal places$).$

The variance of the path other than the critical path $=5\mathrm{.}36$ weeks $($round your response to two decimal places$).$