53.1%

来源: twfx 于 2010-04-23 12:55:08 [旧帖] [给我悄悄话] 本文已被阅读：次

1-P(30,7)/30^7=53.1%

WENXUECITY.COM does not represent or guarantee the truthfulness, accuracy, or reliability of any of communications posted by other users.