名校
解题方法
1 . 给出下列结论:①一组数据
的第
百分位数为
;②若随机变量
,且
,则
;③若将一组数据中的每一个数都加上同一个正数
,则其平均数和方差都会发生变化.其中正确说法的序号为_________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2bdb1faf12a59889ef07f9aa0e2c2b3e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1f959e5f8d89390f0f136f6acc9f6fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c748e40ba21ac5063d3bccaa57ef278.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7795348ccc99540240f53b5d81a3333.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d387ddc97b98af79ddf82cde8f4852b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66161fc8faea9eb09485adafcb5add5c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
您最近一年使用:0次
名校
2 . 垃圾分类是保护环境,改善人居环境、促进城市精细化管理、保障可持续发展的重要举措.某小区为了倡导居民对生活垃圾进行分类,对垃圾分类后处理垃圾
(千克)所需的费用
(角)的情况作了调研,并统计得到表中几组对应数据,同时用最小二乘法得到
关于
的线性回归方程为
,则下列正确说法的序号是_____ .
①变量
之间呈正相关关系;
②可以预测当
时,
的值为6.88;
③表中
的值为3.9;
④样本中心点为
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb44e7bdf09430ce6bf79868ecef8aaa.png)
![]() | 2 | 3 | 4 | 5 |
![]() | 2 | 2.3 | 3.4 | ![]() |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b0fffbec1fe851795dfdd448bf0d165.png)
②可以预测当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22ff06692c025b869a7bcdcff15dca9e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
③表中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
④样本中心点为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/432f5f9278e8f2b88a43bec7a6d5a1aa.png)
您最近一年使用:0次
2024-02-21更新
|
169次组卷
|
2卷引用:河南省南阳市2023-2024学年高二下学期期中考试数学试卷