Joe's Hardware is adding a new product line that will require an investment of exist1, 450, 000. Managers estimates that this investment will have a 10-year life and generate net cash inflows of exist320, 000 the first year, exist300, 000 the second year, and exist225, 000 each year thereafter for eight years. The investment has no residual value. Compute the payback period. First enter the formula, then calculate the payback period. ( )