1 . 给出的下列四个命题中,正确的命题序号为______ .
①从匀速传递的产品生产流水线上,质检员每10分钟从中抽取一件产品进行某项指标检测,这样的抽样是分层抽样;
②设回归直线方程为
,当变量
每增加一个单位时,
平均增加2个单位;
③已知
服从正态分布
,且
,则
;
④变量
与
相对应的一组样本数据为
,
,
,
,由上述样本数据得到
与
的线性回归分析,若
表示解释变量对于预报变量变化的贡献率,则
.
①从匀速传递的产品生产流水线上,质检员每10分钟从中抽取一件产品进行某项指标检测,这样的抽样是分层抽样;
②设回归直线方程为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d2381cdab947725debda9d1b8b1b8f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e3617671ab9daae844ca0a46066fe7a.png)
③已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc7dd47bfd5fc127d0593e503c0b4d6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c757ea3367594d0e5fb7a6cc4f5a73e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44b8643e25bfd7224fd166e813822146.png)
④变量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b52b4f24969673c863b5aff4fb6751ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be54e84508decfcce6d2fcbe6c8c1a92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7e2ef70c5c169e9457daf8f61f1a765.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/224b1749760c2d7854ed597b4fb766d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b12f5329716234ea36d40f9058f8270a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9bf1ef8a272e6cabd3c1f3589b42480f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b52b4f24969673c863b5aff4fb6751ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be54e84508decfcce6d2fcbe6c8c1a92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c85067c53e936ef32da818efe04bdbb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d7e5c143b151c8c682e525a87480e13.png)
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