An anticipated purchase of equipment for $400,000, with a useful life of years and no residual value, is expected to yield the following annual net incomes and net cash flows Year T --- Net Income Net Cash Flow sooooooooo 15000 100,000 9000 90000 80,000 70,00 90,000 8000 90,000 8000 90.000 80,000 90.000 What is the payback period? o o o o