How do I find the IRR percentages without using excel. Please explain it clearly, step by step. Thanks.

The local supermarket is considering investing in self-checkout kiosks for its customers. The self-checkout kiosks will cost $45,500 and have no residual value. Management expects the equipment to result in net cash savings over three years as customers grow accustomed to using the new technology: $14,000 the first year, $21,000 the second year; $27,000 the third year. The company has already determined that the net present value of the investment at a 14% discount rate is $1,152. What is the approximate internal rate of return (IRR) of the kiosk investment? (Click the icon to view the present value of an annuity table.) (Click the icon to view the present value table.) (Click the icon to view the future value of an annuity table.) (Click the icon to view the future value table.) Since the NPV at 14% is the IRR must be 14%. Now calculate the NPV at 16%. (Round your answer to the nearest whole dollar. Use parentheses or a minus sign for a negative NPV.) The NPV is The NPV is at 16%. Therefore, the IRR must be