EXHIBIT 12.4 WEST TEXAS UTILITIES COMPANY RATIO OF EARNINGS TO FIXED CHARGES FOR THE TWELVE MONTHS ENDED SEPTEMBER 30, 1996 (Thousands Except Ratio) (Unaudited) Operating Income $54,590 Adjustments: Income taxes 9,927 Provision for deferred income taxes 1,775 Deferred investment tax credits (1,321) Utility plant development costs, net of tax (10,917) Other income and deductions (150) Allowance for borrowed and equity funds used during construction 1,177 Earnings $55,081 Fixed Charges: Interest on long-term debt $22,385 Interest on short-term debt and other 4,911 Fixed Charges $27,296 Ratio of Earnings to Fixed Charges 2.02 ======