73 EXHIBIT 12.2 PUBLIC SERVICE COMPANY OF OKLAHOMA (CONSOLIDATED) RATIO OF EARNINGS TO FIXED CHARGES FOR THE TWELVE MONTHS ENDED JUNE 30, 1997 (Thousands Except Ratio) (Unaudited) Operating Income $99,671 Adjustments: Income taxes 34,209 Provision for deferred income taxes 3,123 Deferred investment tax credits (2,784) Other income and deductions 138 Allowance for borrowed and equity funds used during construction 2,222 --------- Earnings $136,579 ========= Fixed Charges: Interest on long-term debt $30,676 Amortization of debt issuance cost 1,749 Other interest 4,186 --------- Fixed Charges $36,611 ========= Ratio of Earnings to Fixed Charges 3.73 =========