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1 . 某市电力公司为了制定节电方案,需要了解居民用电情况,通过随机抽样,电力公司获得了
户居民的月平均用电量,分为六组制出频率分布表和频率分布直方图(如图所示).
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/2/1cd69f4f-1c06-452c-9068-8d58bb753772.png?resizew=314)
(1)求
,
的值;
(2)为了解用电量较大的用户用电情况,在第
、
两组用分层抽样的方法选取
户.
①求第
、
两组各取多少户?
②若再从这
户中随机选出
户进行入户了解用电情况,求这
户中至少有一户月平均用电量在
范围内的概率.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e6f1af4b44b2e97e8f319bab4ae9010.png)
组号 | 分组 | 频数 | 频率 |
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/2/1cd69f4f-1c06-452c-9068-8d58bb753772.png?resizew=314)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
(2)为了解用电量较大的用户用电情况,在第
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91e07104b699c4012be2d26160976a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f8c4c029e552954bd493b49aeab82d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91e07104b699c4012be2d26160976a2.png)
①求第
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91e07104b699c4012be2d26160976a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f8c4c029e552954bd493b49aeab82d5.png)
②若再从这
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91e07104b699c4012be2d26160976a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/020de07299195a5a63ff846d8851ae1e.png)
您最近一年使用:0次
2018-03-12更新
|
585次组卷
|
5卷引用:专题5.3 统计与概率(B卷提升篇)-2020-2021学年高一数学必修第二册同步单元AB卷(新教材人教B版)
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2 . 针对国家提出的延迟退休方案,某机构进行了网上调查,所有参与调查的人中,持“支持”、“保留”和“不支持”态度的人数如下表所示:
(1)在所有参与调查的人中,用分层抽样的方法抽取
个人,已知从持“不支持”态度的人中抽取了
人,求
的值;
(2)在接受调查的人中,有
人给这项活动打出的分数如下:
,
,
,
,
,
,
,
,
,
,把这
个人打出的分数看作一个总体,从中任取一个数,求该数与总体平均数之差的绝对值超过
的概率.
支持 | 保留 | 不支持 | |
| |||
|
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b53c7539ed297ea63b9ace6f5cc58ca8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
(2)在接受调查的人中,有
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d07ae0b4264da6a8812454ffd2f20d94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e2fdddbe283eb69e4ce1853ae2bce79.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/577a1fc3790957f00a3c9aae10d17c92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0a9c92b1a9225f35a0a0c599437bd2a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bd7f6174d048177f092ae1a2f5af76a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d85c234e6315f8691dcea8ca0d684d43.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41d41c47f0114cda7ec3337225e2a083.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db302c311437fed577d1111511fd0fc3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8086196253049fcf89b112a8ab73b488.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2d9f4a25aac67131d95ae8ef8b0fc46.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb4287b5b49d2e72fac87fee4cc626d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d07ae0b4264da6a8812454ffd2f20d94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e5db9fa0bc36e2308bd3eecd5e78351.png)
您最近一年使用:0次
2018-10-07更新
|
478次组卷
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3卷引用:9.1 随机抽样(精练)-2022-2023学年高一数学一隅三反系列(人教A版2019必修第二册)
(已下线)9.1 随机抽样(精练)-2022-2023学年高一数学一隅三反系列(人教A版2019必修第二册)【全国百强校】吉林省长春市实验中学2019届高三上学期开学考试数学(文)试题新疆奎屯市第一高级中学2018-2019学年高一下学期期末考试数学(文)试题