In a CPM network, the critical path has four activities as tabulated below: Complete the table and compute the following: a . The expected mean

In a CPM network, the critical path has four activities as tabulated below:

Complete the table and compute the following:

a$.$ The expected mean time $($in days$)$ for the project completion: days

b$.$ The estimated variance $($in days$)$ for the project: days

c$.$ The estimated standard deviation $($in days$)$ for the critical path completion time: days

d$.$ The probability that the critical path for this project will be completed within $\mathrm{70}$ days: $\%$ 

$($Refer to the attached normal distribution table$)$