求解一道Prep上的Math，百思不得其解

comecomo · 发表于 2010-11-5 01:11:04

[attachimg]82195[/attachimg]主要是关于那个句：1 standard deviation...实在不能理解~~
最后选出来是因为，8个数的比例肯定是1/8的倍数。。。。。汗一个先。。。

sdcar2010 · 发表于 2010-11-5 01:28:25

This is very simply.

As the question says: the mean is 10 and the standard deviation is 0.3. So you have a range of 9.7 to 10.3 as the range within 1 standard deviation of the mean. Hence, both 9.4 and 10.5 are out of the range. (8-6)/8 = 75%

comecomo · 发表于 2010-11-5 02:54:36

Thank you very much. I was confused with the expression of "1 standard deviation". Now clear.

This is very simply.

As the question says: the mean is 10 and the standard deviation is 0.3. So you have a range of 9.7 to 10.3 as the range within 1 standard deviation of the mean. Hence, both 9.4 and 10.5 are out of the range. (8-6)/8 = 75%

-- by 会员 sdcar2010 (2010/11/5 1:28:25)

求解一道Prep上的Math，百思不得其解

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