MDU RESOURCES GROUP, INC. COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES AND COMBINED FIXED CHARGES AND PREFERRED STOCK DIVIDENDS Years Ended December 31, 2003 2002 2001 2000 1999 (In thousands of dollars) Earnings Available for Fixed Charges: Net Income (a) $170,956 $148,444 $155,849 $111,028 $ 84,080 Income Taxes (b) 93,751 86,230 98,341 69,650 49,310 264,707 234,674 254,190 180,678 133,390 Rents (c) 9,073 8,156 6,561 3,952 2,018 Interest (d) 54,354 51,393 51,201 51,801 36,539 Total Earnings Available for Fixed Charges $328,134 $294,223 $311,952 $236,431 $171,947 Preferred Dividend Requirements $ 717 $ 756 $ 762 $ 766 $ 772 Ratio of Income Before Income Taxes to Net Income 153% 158% 163% 163% 159% Preferred Dividend Factor on Pretax Basis 1,097 1,194 1,242 1,249 1,227 Fixed Charges (e) 68,141 59,549 57,762 55,753 38,557 Combined Fixed Charges and Preferred Stock Dividends $ 69,238 $ 60,743 $ 59,004 $ 57,002 $ 39,784 Ratio of Earnings to Fixed Charges 4.8x 4.9x 5.4x 4.2x 4.5x Ratio of Earnings to Combined Fixed Charges and Preferred Stock Dividends 4.7x 4.8x 5.3x 4.1x 4.3x (a) Net income excludes undistributed income (loss) for equity investee. (b) Includes income tax benefits of $4,821 associated with the cumulative effect of accounting change for the twelve months ended December 31, 2003. (c) Represents interest portion of rents estimated at 33 1/3%. (d) Represents interest, amortization of debt discount and expense on all indebtedness and amortization of interest capitalized, and excludes amortization of gains or losses on reacquired debt (which, under the Federal Energy Regulatory Commission Uniform System of Accounts, is classified as a reduction of, or increase in, interest expense in the Consolidated Statements of Income) and interest capitalized. (e) Represents rents (as defined above), interest, amortization of debt discount and expense on all indebtedness, and excludes amortization of gains or losses on reacquired debt (which, under the Federal Energy Regulatory Commission Uniform System of Accounts, is classified as a reduction of, or increase in, interest expense in the Consolidated Statements of Income).