Exhibit 11 MAHASKA INVESTMENT COMPANY AND SUBSIDIARIES STATEMENT RE: COMPUTATION OF PER SHARE EARNINGS Three Months Ended Nine Months Ended September 30, September 30, ---------- ---------- ---------- ---------- 2002 2001 2002 2001 ---------- ---------- ---------- ---------- Earnings per Share Information: - ------------------------------- Weighted average number of shares outstanding during the year ........... 3,895,825 3,965,326 3,880,085 3,963,377 Weighted average number of shares outstanding during the year including all dilutive potential shares....................... 3,977,102 4,009,252 3,958,864 3,996,971 Net earnings .............................. $1,471,509 $1,086,860 $4,290,567 $3,058,320 Earnings per share - basic ................ $ 0.38 $ 0.27 $ 1.11 $ 0.77 Earnings per share - diluted .............. $ 0.37 $ 0.27 $ 1.08 $ 0.77