The Bolt Company is considering investing in a wind turbine to generate its own power. Any unused power will be sold back to the local utility company. Between cost savings and new revenues, the company expects to generate $720,000 per year in net cash inflows from the turbine. The turbine would cost $4 million and is expected to have a 20-year useful life with no residual value. Calculate the payback period. First enter the formula, then calculate the payback period. (Enter amounts in the formula as whole dollars and not in millions. Round the payback period to two decimal places.) Payback period years