题目内容
在样本方差的计算式S2=![](http://thumb.1010pic.com/pic6/res/czsx/web/STSource/20131103202517817263624/SYS201311032025178172636015_ST/0.png)
【答案】分析:利用方差计算公式:S2=
[(x1-
)2+(x2-
)2+…+(xn-
)2],n表示样本容量,
为平均数,根据此公式即可得到答案.
解答:解:由于S2=
[(x1-
)2+(x2-
)2+…+(x10-
)2],所以样本容量是10,平均数是20.
故答案为:容量,平均数.
点评:此题考查了方差,在方差公式:S2=
[(x1-
)2+(x2-
)2+…+(xn-
)2]中,n表示的是样本的容量,
表示的是样本的平均数.
![](http://thumb.1010pic.com/pic6/res/czsx/web/STSource/20131103202517817263624/SYS201311032025178172636015_DA/0.png)
![](http://thumb.1010pic.com/pic6/res/czsx/web/STSource/20131103202517817263624/SYS201311032025178172636015_DA/1.png)
![](http://thumb.1010pic.com/pic6/res/czsx/web/STSource/20131103202517817263624/SYS201311032025178172636015_DA/2.png)
![](http://thumb.1010pic.com/pic6/res/czsx/web/STSource/20131103202517817263624/SYS201311032025178172636015_DA/3.png)
![](http://thumb.1010pic.com/pic6/res/czsx/web/STSource/20131103202517817263624/SYS201311032025178172636015_DA/4.png)
解答:解:由于S2=
![](http://thumb.1010pic.com/pic6/res/czsx/web/STSource/20131103202517817263624/SYS201311032025178172636015_DA/5.png)
![](http://thumb.1010pic.com/pic6/res/czsx/web/STSource/20131103202517817263624/SYS201311032025178172636015_DA/6.png)
![](http://thumb.1010pic.com/pic6/res/czsx/web/STSource/20131103202517817263624/SYS201311032025178172636015_DA/7.png)
![](http://thumb.1010pic.com/pic6/res/czsx/web/STSource/20131103202517817263624/SYS201311032025178172636015_DA/8.png)
故答案为:容量,平均数.
点评:此题考查了方差,在方差公式:S2=
![](http://thumb.1010pic.com/pic6/res/czsx/web/STSource/20131103202517817263624/SYS201311032025178172636015_DA/9.png)
![](http://thumb.1010pic.com/pic6/res/czsx/web/STSource/20131103202517817263624/SYS201311032025178172636015_DA/10.png)
![](http://thumb.1010pic.com/pic6/res/czsx/web/STSource/20131103202517817263624/SYS201311032025178172636015_DA/11.png)
![](http://thumb.1010pic.com/pic6/res/czsx/web/STSource/20131103202517817263624/SYS201311032025178172636015_DA/12.png)
![](http://thumb.1010pic.com/pic6/res/czsx/web/STSource/20131103202517817263624/SYS201311032025178172636015_DA/13.png)
![](http://thumb2018.1010pic.com/images/loading.gif)
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