EXHIBIT 12.4 WEST TEXAS UTILITIES COMPANY RATIO OF EARNINGS TO FIXED CHARGES FOR THE TWELVE MONTHS ENDED JUNE 30, 1998 (Thousands Except Ratio) (Unaudited) Operating Income $47,245 Adjustments: Income taxes 19,745 Provision for deferred income taxes (7,459) Deferred investment tax credits (1,321) Other income and deductions 2,357 Allowance for borrowed and equity funds used during construction 872 -------- Earnings $61,439 ======== Fixed Charges: Interest on long-term debt $20,352 Interest on short-term debt and other 4,216 -------- Fixed Charges $24,568 ======== Ratio of Earnings to Fixed Charges 2.50 ========