满分5 >
初中数学试题 >
一个样本为1,3,2,2,a,b,c.已知这个样本众数为3,平均数为2,那么这个...
一个样本为1,3,2,2,a,b,c.已知这个样本众数为3,平均数为2,那么这个样本方差为( )
A.8
B.4
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101192730946481558/SYS201311011927309464815005_ST/0.png)
D.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101192730946481558/SYS201311011927309464815005_ST/1.png)
考点分析:
相关试题推荐
一个不等式组的解集在数轴上表示出来如图所示,则下列符合条件的不等式组为( )
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101192730946481558/SYS201311011927309464815004_ST/images0.png)
A.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101192730946481558/SYS201311011927309464815004_ST/0.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101192730946481558/SYS201311011927309464815004_ST/1.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101192730946481558/SYS201311011927309464815004_ST/2.png)
D.
查看答案
如图,每个小正方形的边长为1,A、B、C是小正方形的顶点,则∠ABC的度数为( )
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101192730946481558/SYS201311011927309464815003_ST/images0.png)
A.90°
B.60°
C.45°
D.30°
查看答案
函数y=
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101192730946481558/SYS201311011927309464815002_ST/0.png)
中自变量x的取值范围是( )
A.x≥-2
B.x≤-2
C.x≠-2
D.x≥-2且x≠2
查看答案
下面的图形中,既是轴对称图形又是中心对称图形的是( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101192730946481558/SYS201311011927309464815001_ST/images0.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101192730946481558/SYS201311011927309464815001_ST/images1.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101192730946481558/SYS201311011927309464815001_ST/images2.png)
D.
查看答案
-
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101192730946481558/SYS201311011927309464815000_ST/0.png)
是
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101192730946481558/SYS201311011927309464815000_ST/1.png)
的( )
A.相反数
B.倒数
C.绝对值
D.算术平方根
查看答案