EXHIBIT 12.4 WEST TEXAS UTILITIES COMPANY RATIO OF EARNINGS TO FIXED CHARGES FOR THE TWELVE MONTHS ENDED SEPTEMBER 30, 1998 (Thousands Except Ratio) (Unaudited) Operating Income $57,567 Adjustments: Income taxes 31,117 Provision for deferred income taxes (11,407) Deferred investment tax credits (1,321) Other income and deductions 2,445 Allowance for borrowed and equity funds used during construction 1,087 -------- Earnings $79,488 ======== Fixed Charges: Interest on long-term debt $20,352 Interest on short-term debt and other 4,406 -------- Fixed Charges $24,758 ======== Ratio of Earnings to Fixed Charges 3.21 ========