If you insulate your office for $23,000, you will save $2,300 a year in heating expenses. These savings will last forever. a. and b. What is the NPV of the investment when the cost of capital is 8%? What if it is 10%? Cost of NPV Capital a. 8% b. 10% c. What is the IRR of the investment? Note: Enter your answer as a whole percent. IRR % d. What is the payback period on this investment? Payback period years