1 . 有下列结论:
①某年级有男生
人,女生
人,用分层抽样的方法从该年级学生中抽取一个容量为
的样本,则此样本中男生人数为
;
②一个容量为
的样本中数据的最大值是
,最小值是
,组距是
,则列频率分布表时应将样本数据分为
组;
③若
关于
的线性回归方程为
,其中
的取值依次为
,
,
,
,
,则
;
④用一组样本数据
,
,
,
,
估计总体的标准差,若样本的平均数为
,则估计总体的标准差为
.
其中正确的有__________ .(填写所有正确结论的序号)
①某年级有男生
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c889d1b18a0c98d18cf99b7878cec350.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33d848b410318b14f82111491a042dd2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/514e9fb0780f5034a50554c9cf0c15ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3864983798fe836a591e13783fd9e82.png)
②一个容量为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1f959e5f8d89390f0f136f6acc9f6fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17e85c53a287e873f35c9ca64972023c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e595b1cc755cf0dd076e91cf9e9a3e5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d07ae0b4264da6a8812454ffd2f20d94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8d02ea8c4988c5c28ab93f0d70fb55a.png)
③若
![](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/e3d6417d2b22f49c6d40286e12e2e781.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd3304e23f3b0f9569c4140ca89b6498.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f8c4c029e552954bd493b49aeab82d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/180ea775f2af05650404d764384e7faa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b7f27ebcef70a3ebbbe8d2e53ea0896.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/784ee235badd54e39f2f7cecbc99a610.png)
④用一组样本数据
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd3304e23f3b0f9569c4140ca89b6498.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d07ae0b4264da6a8812454ffd2f20d94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d0b71b8d2c183154221f717ce09077b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8d02ea8c4988c5c28ab93f0d70fb55a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d07ae0b4264da6a8812454ffd2f20d94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
其中正确的有
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