4. A construct project consists of 15 activities. Using the CPM method, the following table has been inferred, which represents the duration, earliest start, and latest start of each activity. (20 pts) Direct cost is assumed to be linearly proportional to the duration of each activity according to the following relationship: Direct Cost =$2,000 Duration a) Complete the table by adding the direct cost column. b) Calculate the direct-cost outflow for each day based on both earliest and latest start days and report the results in a table. (Please include the bar charts for both earliest and latest start days too) c) Plot the direct-cost outflow diagram per days for both earliest and latest start days. d) Assume that contractor's bid is $220,000, the overhead cost is $500 per day (should be added to the direct-costs calculated in step b ), and each week has 5 working days. Taking the earliest start day as the reference, if the contractor is paid uniformly in four installments on a biweekly basis (starting from day 0 ), draw a diagram showing both total cost (outflow) and inflow. e) At day 20, is the balance positive or negative? At this day, what are the percentages of total outflow and inflow