xon, a small oil equipment company, purchased a new petroleum drilling rig for $2,000,000. xon will depreciate it using macrs depreciation. the drilling rig has been leased to a firm, which will pay xon $750,000 per year for 8 years. after 8 years the drilling rig will belong to the firm. the firm has a 26% combined marginal income tax rate. what is the after-tax rate of return