deviation 离差是什么东西呀

songxuebest

TR

tomorrow1992

数列中的数值和平均数的偏差值
就是两者之差
不知道是不是这么理解的

iamcrystal

应该是每个数和平均数的差的和再除以总共有多少个数

siani

同意一楼的！di=ai-E
即：第i个数的偏差=第i个数-这个数列的平均数E

tt3tt

我也正想问 今天做了好几道都不会。有谁能给讲一下概念么
我爸不会的题贴一下啊

110.    11364-!-item-!-187;#058&007646
The residents of Town X participated in a survey to determine the number of hours per week each resident spent watching television.  The distribution of the results of the survey had a mean of 21 hours and a standard deviation of 6 hours.  The number of hours that Pat, a resident of Town X, watched television last week was between 1 and 2 standard deviations below the mean.  Which of the following could be the number of hours that Pat watched television last week?

(A) 30
(B) 20
(C) 18
(D) 12
(E) 6



106.    11122-!-item-!-187;#058&007588
If a certain sample of data has a mean of 20.0 and a standard deviation of 3.0, which of the following values is more than
2.5 standard deviations from the mean?

(A) 12.0
(B) 13.5
(C) 17.0
(D) 23.5
(E) 26.5

有人嫩通俗讲解下么

dbk89221

我也正想问 今天做了好几道都不会。有谁能给讲一下概念么
我爸不会的题贴一下啊

110.    11364-!-item-!-187;#058&007646
The residents of Town X participated in a survey to determine the number of hours per week each resident spent watching television.  The distribution of the results of the survey had a mean of 21 hours and a standard deviation of 6 hours.  The number of hours that Pat, a resident of Town X, watched television last week was between 1 and 2 standard deviations below the mean.  Which of the following could be the number of hours that Pat watched television last week?

(A) 30
(B) 20
(C) 18
(D) 12
(E) 6



106.    11122-!-item-!-187;#058&007588
If a certain sample of data has a mean of 20.0 and a standard deviation of 3.0, which of the following values is more than
2.5 standard deviations from the mean?

(A) 12.0
(B) 13.5
(C) 17.0
(D) 23.5
(E) 26.5

有人嫩通俗讲解下么

-- by 会员 tt3tt (2010/8/11 0:30:02)

筒子想复杂了肯定
第一题说的是看电视的时间，均值21 sd=6 pat看电视的时间在1-2倍sd  below   就是在（21-6*2  ，21-6）之间就是（9,15）  选D
第二题说均值20，sd=3   问一下哪个数与均值距离大于2.5倍sd         （20-7.5  ， 20+7.5） 就是要么小于12.5 要么大于27.5  选A

sjmdlyc

好亲切的统计题~

tt3tt

瞬间理解。谢谢哈