Problem 9-4 Calculating Discounted Payback (LO3] An investment project has annual cash inflows of $4,200, $5,100, $6,300, and $5,500. for the next four years, respectively. The discount rate is 15 percent. a. What is the discounted payback period for these cash flows if the initial cost is $6,900? (Do not round intermediate calculations and round your answer to 2 decimal places, e.g., 32.16.) b. What is the discounted payback period for these cash flows if the initial cost is $9,000? (Do not round intermediate calculations and round your answer to 2 decimal places, e.g., 32.16.) c. What is the discounted payback period for these cash flows if the initial cost is $12,000? (Do not round intermediate calculations and round your answer to 2 decimal places, e.g., 32.16.) years a. Discounted payback period b. Discounted payback period c. Discounted payback period years years