6- Any one of five machines can be used in a certain phase of a canning operation. The costs of the machines are shown below and all are expected to have a 10-year life. If the company's minimum attractive rate of return is 18% per year, determine which machine should be selected using (a) the incremental-rate-of-return method, and (b) the present-worth method. Machine 1 2 3 First cost Annual operating cost Annual operating cost $28,000 20,000 $30,000 $33,000 18,000 28,000 $225000 25,000 35,000 $51,000 12,000 32,000 $46,000 14,000 24,000 6- Any one of five machines can be used in a certain phase of a canning operation. The costs of the machines are shown below and all are expected to have a 10-year life. If the company's minimum attractive rate of return is 18% per year, determine which machine should be selected using (a) the incremental-rate-of-return method, and (b) the present-worth method. Machine 1 2 3 First cost Annual operating cost Annual operating cost $28,000 20,000 $30,000 $33,000 18,000 28,000 $225000 25,000 35,000 $51,000 12,000 32,000 $46,000 14,000 24,000