Heidi Company is considering the acquisition of a machine that costs $506,000. The machine is expected to have a useful life of 6 years, a negligible residual value, an annual net cash flow of $125,000, and annual operating income of $82,261. What is the estimated cash payback period for the machine (round to one decimal point)? 5.0 year 4.0 years 6.5 years 6.2 years