7. Consider the following activity on arc project description withassociated cost data. The cost data represents the total cost andshould be considered linear with time.NORMAL CRASHACTIVITY DURATION COST DURATION COST(1,4) 2 80 1 130(1,2) 3 70 1 190(1,3) 6 110 5 135(2,3) 2 90 1 100(2,4) 4 60 3 100(2,5) 7 85 6 115(3,5) 3 50 2 70(4,5) 4 105 3 175a. Draw the precedence network diagram.b. Compute the critical path, associated time and cost (normal time).c. Reduce the project duration to 9 days at minimum cost? What is the critical path and cost?d. Reduce the project to minimum duration and calculate the cost.