EXHIBIT 12.2 PUBLIC SERVICE COMPANY OF OKLAHOMA (CONSOLIDATED) RATIO OF EARNINGS TO FIXED CHARGES FOR THE TWELVE MONTHS ENDED MARCH 31,1999 (Thousands Except Ratio) (Unaudited) Operating Income $112,733 Adjustments Income taxes 49,732 Provision for deferred income taxes (58) Deferred investment tax credits (1,763) Other income and deductions (1,440) Allowance for borrowed and equity funds used during construction 1,815 ----------- Earnings $161,019 =========== Fixed Charges: Interest on long-term debt $28,128 Interest on short-term debt and other 4,046 Distributions on Trust Preferred Securities 6,000 ----------- Fixed Charges $38,174 =========== Ratio of Earnings to Fixed Charges 4.22 ===========