Exhibit 12 (b) 1 1 PUBLIC SERVICE COMPANY OF OKLAHOMA CONSOLIDATED RATIO OF EARNINGS TO FIXED CHARGES FOR YEARS ENDED DECEMBER 31 1994 1993 1992 1991 1990 (thousands except ratios) Operating income $ 98,258 $72,156 $78,096 $ 86,796 $ 92,461 Adjustments: Federal and state income taxes 27,954 13,554 (835) 18,321 27,420 Provision for deferred federal and state income taxes 7,779 9,537 21,157 10,133 (4,434) Deferred investment tax credits (2,789) (2,838) (2,711) (2,925) (2,736) Other income and deductions 933 531 (940) (1,667) 20 Allowance for borrowed and equity funds used during construction 2,513 1,948 740 1,931 1,678 Interest portion of financing leases -- 17 37 34 43 Earnings $134,648 $94,905 $95,544 $112,623 $114,452 Fixed charges: Interest on long-term debt $29,594 $31,410 $30,688 $30,545 $30,545 Interest on short-term debt and other 3,844 2,729 1,646 3,286 8,532 Interest portion of financing leases -- 17 37 34 43 Fixed Charges $33,438 $34,156 $32,371 $33,865 $39,120 Ratio of Earnings to Fixed Charges 4.03 2.78 2.95 3.33 2.93