Please help with this case study. I will give like and thanks in advance

Case Study The project described in the table below is at the end of its sixth week: Activity Predecessors Duration (Wks) Budget ($) Actual Cost ($) % Complete a N 300 400 100 b 3 200 180 100 a 2 250 300 100 d a 5 600 400 20 e b.c 4 400 200 20 Answer these questions about this project: 1) Find the cost and schedule variances. 2) Find the CPI and SPI. 3) Find the critical ratio of the project using earned value calculations. 4) Calculate the ETC and EAC for the project. Note: I want answers 1-4 to be at the project level, not at the per-activity level. Hint: Since you are asked to calculate a number of Earned Value metrics, you should start by computing the AC, EV and PV. Be careful calculating the PV-you see that activities "d" and "e" are only 20% complete at the end of 6 weeks- what was their planned percent of completion based on predecessors and durations? To find this, you can draw yourself a little network diagram showing the predecessors with their durations (you don't need to show this drawing if you do one.) Your answers should be submitted in an MS-Excel file format. You are required to show your work in completing the calculations