3) A mining can be purchased and installed for $90,000. It is expected to be kept in service for eight years. Its salvage value is estimated as $10,000 at the end of year eight. The net annual value added (i.e., revenues less expenses) that can be attributed to this machine is constant over eight years and amounts to $15,000. An effective income tax rate of 40% is used by the company, and the after-tax MARR equals 15% per year. (a) Set up a table and calculate ATCF. (20 points) (b) Is this machine economically justified? (10 points)