Exhibit 11
Tetra Tech, Inc.
Computation of Net Income Per Common Share
(Unaudited)
Three Months Ended Six Months Ended
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March 29, March 30, March 29, March 30,
1998 1997 1998 1997
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Basic:
Common stock outstanding, beginning
of period . . . . . . . . . . . . . . . 22,272,741 17,805,262 20,714,254 17,658,752
Stock options exercised. . . . . . . . . . 105,013 56,570 123,954 75,171
Issuance of common stock . . . . . . . . . 61,606 184,365 1,601,406 312,274
Payment of fractional shares . . . . . . . -- -- (254) --
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Common stock outstanding, end
of period . . . . . . . . . . . . . . . 22,439,360 18,046,197 22,439,360 18,046,197
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Weighted average common stock
outstanding during the period . . . . . 22,323,748 17,845,031 22,048,636 17,766,460
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Total . . . . . . . . . . . . . . . 22,323,748 17,845,031 22,048,636 17,766,460
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Net income as reported in condensed
consolidated financial statements . . . $ 4,521,000 $ 2,872,000 $ 8,571,000 $ 5,468,000
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Basic Earnings Per Share . . . . . . . . . $ 0.20 $ 0.16 $ 0.39 $ 0.31
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Diluted:
Weighted average common shares
outstanding during the period . . . . . 22,323,748 17,845,031 22,048,636 17,766,460
Potential common shares under the
treasury stock method assuming the
exercise of options and warrants. . . . 841,190 446,616 1,067,146 559,918
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Total . . . . . . . . . . . . . . . 23,164,938 18,291,648 23,115,782 18,326,378
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Net income as reported in condensed
consolidated financial statements . . . $ 4,521,000 $ 2,872,000 $ 8,571,000 $ 5,468,000
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Diluted Earnings Per Share . . . . . . . . $ 0.20 $ 0.16 $ 0.37 $ 0.30
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See accompanying notes to the condensed consolidated financial statements.