Foe number 8 I got 2.60 years (is this correct). I need help with number 9 and where to plug in numbers to.

8. Calculating IRR. What is the IRR of the following set of cash flows? Year Cash Flow 0 1 2 -$2,200 640 800 1,900 9. Calculating NPV. For the cash flows in the previous problem, what is the NPV at a discount rate of zero percent? What if the discount rate is 10 percent? If it is 20 percent? If it is 30 percent