a. The averaqe rate of return, giving effect to straight-line depreciation on the investment. If required, round your answer to one decimal place. % b. The cash payback period. Feedbask T Check My Work b. Divide the amount to be invested by the annual net cash inflow. c. Subtract the cost from the present value of the annual net cash flow. (Use the present value of an annuity factor for 10 periods at 12%, refer Exhibit 5 in the text.)