Please use excel, need help with functions and setting up cash flows in Excel because I am only used to using a financial calculator, thanks!

4. The following cash-flow pattern has two IRRs. Use Excel to draw a graph of the NPV of these cash flows as a function of the discount rate. Then use the IRR function to identify the two IRRs. Would you invest in this project if the opportunity cost were 20%? 4 6 8 Year Cash flow 500 600 300 300 200 -1,000 3 4