凭海_临风
幼苗
共回答了12个问题采纳率:100% 举报
设
![](https://img.yulucn.com/upload/b/60/b6076c7123c6b4dfa33b4267543e8827_thumb.jpg)
,…,
![](https://img.yulucn.com/upload/7/05/705f6b3ff97f4930f45ce223a4917ba0_thumb.jpg)
是变量
![](https://img.yulucn.com/upload/5/a8/5a823b6fb37737a6442b8e2c706f5c6d_thumb.jpg)
和
![](https://img.yulucn.com/upload/9/10/91015be6112e0e5bbfd619b0dba7fc68_thumb.jpg)
的
![](https://img.yulucn.com/upload/0/a5/0a50a2972c4a8b77a5cba969f5a74f35_thumb.jpg)
个样本点,直线
![](https://img.yulucn.com/upload/4/99/499e668625685b1172727b7bb6ddf9a2_thumb.jpg)
是由这些样本点通过最小二乘法得到的线性回归方程(如图),以下结论中正确的是( )
A.
![](https://img.yulucn.com/upload/5/a8/5a823b6fb37737a6442b8e2c706f5c6d_thumb.jpg)
和
![](https://img.yulucn.com/upload/9/10/91015be6112e0e5bbfd619b0dba7fc68_thumb.jpg)
的相关系数为直线
![](https://img.yulucn.com/upload/4/99/499e668625685b1172727b7bb6ddf9a2_thumb.jpg)
的斜率
B.
![](https://img.yulucn.com/upload/5/a8/5a823b6fb37737a6442b8e2c706f5c6d_thumb.jpg)
和
![](https://img.yulucn.com/upload/9/10/91015be6112e0e5bbfd619b0dba7fc68_thumb.jpg)
的相关系数在0到1之间
C.当
![](https://img.yulucn.com/upload/0/a5/0a50a2972c4a8b77a5cba969f5a74f35_thumb.jpg)
为偶数时,分布在
![](https://img.yulucn.com/upload/4/99/499e668625685b1172727b7bb6ddf9a2_thumb.jpg)
两侧的样本点的个数一定相同
D.直线
![](https://img.yulucn.com/upload/4/99/499e668625685b1172727b7bb6ddf9a2_thumb.jpg)
过点
D
因为线性回归方程必定过样本中心点
![](https://img.yulucn.com/upload/e/87/e872de5a8f11eacd73f26546a7b75954_thumb.jpg)
,D正确;
![](https://img.yulucn.com/upload/5/a8/5a823b6fb37737a6442b8e2c706f5c6d_thumb.jpg)
和
![](https://img.yulucn.com/upload/9/10/91015be6112e0e5bbfd619b0dba7fc68_thumb.jpg)
的相关系数不是直线的斜率,A错;
![](https://img.yulucn.com/upload/5/a8/5a823b6fb37737a6442b8e2c706f5c6d_thumb.jpg)
和
![](https://img.yulucn.com/upload/9/10/91015be6112e0e5bbfd619b0dba7fc68_thumb.jpg)
的相关系数在-1和1之间,B错误;C中,分布在l两侧的点的个数不一定相同,因此C错误,选D
1年前
10