Problem 8-6 Calculating NPV [LO 4) For the given cash flows, suppose the firm uses the NPV decision rule. Year Cash Flow WN - 157,300 74,000 87,000 46,000 a. At a required return of 9 percent, what is the NPV of the project? (Do not round intermediate calculations and round your answer to 2 decimal places, e.g., 32.16.) b. At a required return of 21 percent, what is the NPV of the project? (A negative answser should be indicated by a minus sign. Do not round intermediate calculations and round your answer to 2 decimal places, e.g., 32.16.) a. NPV b. NPV