1,2,3,4,平均数为3.1求有几种排列组合方式
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![1,2,3,4,平均数为3.1求有几种排列组合方式](/uploads/image/z/4021834-58-4.jpg?t=1%2C2%2C3%2C4%2C%E5%B9%B3%E5%9D%87%E6%95%B0%E4%B8%BA3.1%E6%B1%82%E6%9C%89%E5%87%A0%E7%A7%8D%E6%8E%92%E5%88%97%E7%BB%84%E5%90%88%E6%96%B9%E5%BC%8F)
1,2,3,4,平均数为3.1求有几种排列组合方式
1,2,3,4,平均数为3.1求有几种排列组合方式
1,2,3,4,平均数为3.1求有几种排列组合方式
sxyhjmyxgs ,
这题分有3参与与没3参与两种情况:
没3,则必须是(2,4)(4,2)共2种.
有3,则必须是(2,3,4)(2,4,3)(3,2,4)(3,4,2)(4,2,3)(4,3,2)共6种
按分类相加,总共有,8种.
平均数为2.5,你算错了!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!...
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平均数为2.5,你算错了!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!1!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
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