4. Proposals L and K each cost $500,000, have 6-year lives, and have expected total cash flows of $720,000. Proposal L is expected to provide equal annual net cash flows of $120,000, while the net cash flows for Proposal K are as follows: Year 1 $250,000 200,000 Year 2 Year 3 100,000 Year 4 90,000 60,000 Year 5 Year 6 20.000 $720,000 Determine the cash payback period for each proposal