Exhibit 12.4 West Texas Utilities Company Ratio of Earnings to Fixed Charges For Years Ended December 31 1995 1994 1993 1992 1991 (thousands, except ratios) Operating income $59,486 $54,763 $46,576 $57,302 $57,925 Adjustments: Income taxes 6,456 7,900 10,869 12,387 13,283 Provision for deferred income taxes 1,971 8,377 3,593 6,426 5,216 Deferred investment tax credits (1,321) (1,321) (1,321) (1,515) (1,349) Other income and deductions (463) 4,210 1,907 1,114 1,603 Allowance for borrowed and equity funds used during construction 1,030 474 247 156 146 Earnings $67,159 $74,403 $61,871 $75,870 $76,824 Fixed charges: Interest on long- term debt $21,413 $18,547 $19,225 $21,368 $21,339 Interest on short- term debt and other 4,110 3,534 2,988 2,197 1,967 Fixed charges $25,523 $22,081 $22,213 $23,565 $23,306 Ratio of earnings to fixed charges 2.63 3.37 2.79 3.22 3.30