(Ignore income taxes in this problem.) Overland Corporation has gathered the following data on a proposed investment project: Investment required in equipment $ 600,000 Annual cash inflows $ 64,000 Salvage value of equipment $ 0 Life of the investment 15 years Required rate of return 6 % The company uses straight-line depreciation on all equipment. Assume cash flows occur uniformly throughout a year except for the initial investment. The payback period for the investment is: