Using the information provided in the table below, do the following:

a$.$ Construct a network diagram.

b$.$ Determine which activities are on the critical path.

c$.$ Compute the length of the critical path.

$\backslash$table$[[$Activity$,$Estimated time $($days$)],[1->2,5],[2->3,6],[2->4,4],[3->6,9],[6->7,2],[4->5,4],[4->7,18],[5->7,10]]$