SOUTHWESTERN PUBLIC SERVICE COMPANY EXHIBIT 12. Statement of Computation of Ratio of Earnings Twelve Months Ended November 30, 1995 (Dollars In Thousands) Computation of Ratio of Earnings to Fixed Charges: Fixed charges, as defined: Interest on long-term debt $ 41,992 Amortization of debt premium, discount and expense 541 Other interest 3,125 Estimated interest factor of rental charges 1,292 Total fixed charges $ 46,950 Earnings as defined: Net earnings per statement of earnings $121,477 Fixed charges as shown 46,950 Income taxes: Federal-current 56,923 Federal-deferred 10,372 State 1,963 Investment tax credits (250) Earnings available for fixed charges $237,435 Ratio of earnings to fixed charges 5.06 Computation of Ratio of Earnings to Fixed Charges and Preferred Dividend Requirements Combined: Total fixed charges, as shown above $ 46,950 Preferred dividend requirements* 7,602 Total fixed charges and preferred dividend requirements combined $ 54,552 Earnings available for fixed charges and preferred dividend requirements combined $237,435 Ratio of earnings to fixed charges and preferred dividend requirements combined 4.35 *Preferred dividend requirements: Annual preferred dividend requirement $ 4,878 Less amount deductible for income tax purposes 82 Net requirement [A] $ 4,796 1 / (100% - effective rate) [B] 1.568 Effective tax rate 36.2% [A] x [B] $ 7,520 Add amount deductible for income tax purposes 82 Preferred dividend requirements $ 7,602