Five years ago a chemical plant invested $84,000 in a pumping station on a nearby river to provide the water required for their production process. Straight-line depreciation is employed for tax purposes, using a 30-year life and zero salvage value. During the past five years, annual operating costs have been as follows: Maintenance $1, 800 Power and Labor $4, 100 Taxes and insurance $800 A nearby city has offered to purchase the pumping station for $70,000 as it is in the process of developing a city water distribution system. The city is willing to sign a 10-year contract with the plant to provide the plant with its required volume of water for a price of $12,000 per year. Plant officials estimate that the salvage value of the pumping station 10 years hence will be about $28,000. The before-tax MARR is 18 % per year. An effective income tax rate of 50% is to be assumed. Compare the after-tax equivalent uniform annual cost EUAC, of the defender (keeping the pumping station) to the challenger (sell station to the city). To answer this problem, calculate the value of the difference in annual costs: EUAC (challenger)-EUAC(defender). (Enter your answer as a number without the dollar $ sign.) Machine A was purchased three years ago for $38,000 and had an estimated MV of $4,000 at the end of its 10-year life. Annual operating $3, 200. The machine will perform satisfactorily for the next seven years. A salesperson for another company is offering Machine B for $40,000 with an MV of $7, 500 after 10 years. Annual operating costs will be $2, 700. Machine A could be sold now for $30,000, and MARR is 15% per year. Compare the before-tax equivalent uniform annual cost, EUAC, of the defender (keeping Machine A) to the challenger (buying Machine B). To answer this problem, calculate the value of the difference in annual costs: EUAC (challenger)