从一批螺栓中随机抽取6个，测量其长度（单位：mm）分别为：60，61，58，61，59，61，试估计这批螺栓长度 X 的数学期望为（）mm正确答案是：60 - 查题网

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国家开放大学 / 数理统计

从一批螺栓中随机抽取6个，测量其长度（单位：mm）分别为：60，61，58，61，59，61，
试估计这批螺栓长度 X 的数学期望为（）mm

正确答案是：60

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数理统计

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