EXHIBIT 12.3 PUBLIC SERVICE COMPANY OF OKLAHOMA (CONSOLIDATED) RATIO OF EARNINGS TO FIXED CHARGES FOR THE TWELVE MONTHS ENDED SEPTEMBER 30, 1995 (Thousands Except Ratio) (Unaudited) Operating Income $114,568 Adjustments: Federal and state income taxes 39,061 Provision for deferred Federal and state income taxes 3,558 Deferred investment tax credits (2,789) Other income and deductions 2,777 Allowance for borrowed and equity funds used during construction 4,682 Earnings $161,857 Fixed Charges: Interest on long-term debt $ 29,594 Amortization of debt issuance cost 1,568 Other interest 4,192 Fixed Charges $ 35,354 Ratio of Earnings to Fixed Charges 4.58