Petroleum Development Corporation Index to Exhibits 11 Schedule of Computation of Net Income Per Share E-2 E-1 PETROLEUM DEVELOPMENT CORPORATION AND SUBSIDIARIES EXHIBIT 11 SCHEDULE OF COMPUTATION OF NET INCOME PER SHARE Years Ended December 31, BASIC 1997 1996 1995 Net income for basic income per common share $ 7,586,800 3,549,400 $1,481,500 Weighted average number of common shares outstanding during the year 11,278,800 10,449,137 11,056,441 Basic earnings per share $ .67 $ .34 $ .13 DILUTED Net income for basic earnings per common share $ 7,586,800 $ 3,549,400 $ 1,481,500 Net income for diluted earnings per share $ 7,586,800 $ 3,549,400 $ 1,481,500 Weighted average number of shares used in calculating basic earnings per common share 11,278,800 10,449,137 11,056,441 Shares issuable for diluted calculation 1,261,365 1,093,178 554,723 Weighted average number of shares used in calculation of diluted earnings per share 12,540,165 11,542,315 11,611,164 Diluted earnings per share $ .61 $ .31 $ .13 E-2