4. Ten years ago T-Bone Company purchased a drill for $250,000. It was being depreciated on a straight line basis to an estimated $25,000 salvage value over a 15 year period. The firm is considering selling the old drill and purchasing a new one that would cost $500,000. The firms marginal tax rate is 40%. Determine the NINV required to purchase the new drill, if the old drill is sold for $100,000. show work