A project consists of five activities. Naturally the paint mixing precedes the painting activities. Also, both ceiling painting and floor sanding must be done prior to floor buffing. Optimistic Most Probable Pessimistic Activity Time (hr) Time (hr) Time (hr) Floor sanding 3 4 5 Floor buffing 1 2 3 Paint mixing 0.5 1 1.5 Wall painting 1 2 9 Ceiling painting 1 5.5 7 ​ Construct the PERT/CPM network for this problem on a rough paper. What is the expected completion time of this project? What is the probability that the project can be completed within 9 hr.?