名校
解题方法
1 . 某班有45名同学,一次考试后的数学成绩服从正态分布
,则理论上在85分到90分的人数约是________ .(按四舍五入法保留整数)
附:
,
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3e58d71900e4637dfbf5d0e6cac7e2f.png)
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b70b1352f55fec00ae8705936b55c5ef.png)
附:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/256181dd02e41f3a9eadf1de097f472e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0cee36a73c750c9229a4a4f4683cbcd3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3e58d71900e4637dfbf5d0e6cac7e2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8db887b7b3219f7afb54461d74129ed1.png)
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2023-05-24更新
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1035次组卷
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4卷引用:四川省绵阳市江油市江油中学2022-2023学年高二下学期期末数学理科试题