Melody_wan 发表于 2009-4-13 11:56:31

有个数学题不懂！

本帖最后由 Melody_wan 于 2009-4-13 16:00 编辑

1.Is the standard deviation of the set of measurements X1,X2,X3,X4,…,X20, less than 3?

(1)The variance for the set of measurement is 4.

(2)For each measurement,the difference between the mean and that measurement is 2.


哪位大人指导下吖~~

dylan.lq 发表于 2009-4-14 22:09:03

OG 11th, P58有很详细的解释啊
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