名校
1 . 给出下列说法:
(1)命题“
,
”的否定形式是“
,
”;
(2)已知
,则
;
(3)已知回归直线的斜率的估计值是2,样本点的中心为
,则回归直线方程为
;
(4)对分类变量
与
的随机变量
的观测值
来说,
越小,判断“
与
有关系”的把握越大;
(5)若将一组样本数据中的每个数据都加上同一个常数后,则样本的方差不变.
其中正确说法的个数为( )
(1)命题“
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0c7a319f1fb9ef4cd6bd9eb5ab0c53b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea97dc49e5857619425953f88245fdf6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c780149aef1bd77162e85f7f8906a6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae19515516016bb679a5bda763e0ba59.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed6e3e55bcdd39823a8e59ac30fb9ed4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f527e1add10f68fbb559d425af6217df.png)
(3)已知回归直线的斜率的估计值是2,样本点的中心为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1beb189381103ad1e758fd8cfedb6355.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88268a2e8aeb1beceaf04b81225cebd5.png)
(4)对分类变量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a829fdd8ec0f3b7ede883cf2c3e53b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2581192317ef233ccdccfc48ac29b52b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a829fdd8ec0f3b7ede883cf2c3e53b.png)
(5)若将一组样本数据中的每个数据都加上同一个常数后,则样本的方差不变.
其中正确说法的个数为( )
A.2 | B.3 | C.4 | D.5 |
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