4) New equipment is under consideration for purchase. It has an initial cost of $120,000 and an estimated useful life of four years. The machine will be depreciated using the MACRS 3 year class schedule. It is expected to result in labor savings of $50,000 for each year of operation. (20 points) a) What is the prospective after-tax rate of return for this asset? Assume that the company uses a tax rate of 50%. Include interpolation in your analysis. b) If the airlines internal MARR is 15%, should the new machine be purchased? What is the basis for your