required rate of return is 11 percent (this is the same data as the previous exercise). Required: a. Use trial and error to approximate the internal rate of return for this investment proposal. b. Should the company purchase the harvesting machine? Explain. machine for $100,000. The machine is expected to have a life of 4 years, and a salvage value of $20.00 Annual maintenance costs will total $28,000. Annual savings are predicted to be $60,000. The company