Calculating Payback An investment project provides cash inflows of $865 per year for eight years. What is the project payback period if the initial cost is $3,100? What if the initial cost is $4,300? What if it is $7,900? Calculating NPV For the cash flows in the previous problem, suppose the firm uses the NPV decision rule. At a required return of 9 percent, should the firm accept this project? What if the required return was 21 percent