![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/23/6649b6eb-4568-4862-99b0-eeb5bb379e48.png?resizew=207)
A.![]() | B.![]() | C.![]() | D.![]() |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1933311c0c090e1138e4dd388b7adf8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://img.xkw.com/dksih/QBM/2020/9/22/2555288282529792/2555453005266944/STEM/4f589e05908b4d66a1c6adb823258c75.png?resizew=301)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2302f08a4b2f2bed333a6732ca64bc89.png)
(2)统计方法中,同一组数据常用该组区间的中点值(例如区间
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b016914bacd4ba7adb8670de550ce089.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aca74e3bfe66db258ab238ecf3b08b47.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39197d0d24e19b4f9ed686e2e97a69cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632244ea6931507f8656e1cc3437d392.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b06e95b57b7a81cd81d05557a11fa92.png)
3 . 教育是阻断贫困代际传递的根本之策.补齐贫困地区义务教育发展的短板,让贫困家庭子女都能接受公平而有质量的教育,是夯实脱贫攻坚根基之所在.治贫先治愚,扶贫先扶智.为了解决某贫困地区教师资源匮乏的问题,某市教育局拟从5名优秀教师中抽选人员分批次参与支教活动.支教活动共分3批次进行,每次支教需要同时派送2名教师,且每次派送人员均从这5人中随机抽选.已知这5名优秀教师中,2人有支教经验,3人没有支教经验.
(1)求5名优秀教师中的“甲”,在这3批次支教活动中恰有两次被抽选到的概率;
(2)求第一次抽取到无支教经验的教师人数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f8c4c029e552954bd493b49aeab82d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/029d393bb07b7140905b85f550519de4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8664a837eed36c57a7af7ce08bf47a4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32224f45e90ed9f702adad1200316e44.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ce3aecc693bc2e03cddb2226bb65e31.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5211ec83320c7578d4c102eef4ff714f.png)
A.![]() | B.![]() | C.![]() | D.![]() |
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/31/fcf79955-6bc9-4678-b9bf-71e3f9377787.png?resizew=244)
(1)补全频率分布直方图;
(2)若同一组数据用该组区间的中点值作为代表,据此估计这种产品质量指标值的平均数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c85481cd7e94130ef3aa05b4a39e79cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/671f43c79d612c93a6d160335e86e177.png)
(3)当一件产品的质量指标值位于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85f650f843ea91e4f58ed48a2d2da860.png)
(1)请补全
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b72fcdc709e77910cd36a26369648b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ead9d6ff51996f3ebace6f212e11a9e4.png)
课间不经常进行体育活动 | 课间经常进行体育活动 | 合计 | |
男 | |||
女 | |||
合计 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
附表:
0. 1 | 0. 05 | 0. 01 | 0. 005 | 0. 001 | |
2. 706 | 3. 841 | 6. 635 | 7. 879 | 10. 828 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2187714e660234f0b72f2b47d3ea685a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/356b05e46b10ee51c3e43546d73ec96c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c8e63a3de229aa35d7e95b166802303.png)
选考物理 | 选考历史 | 总计 | |
男生 | 40 | 50 | |
女生 | |||
总计 | 30 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b72fcdc709e77910cd36a26369648b3.png)
(Ⅱ)从这100人中按照分层抽样的方法选取10人参加座谈会.试问参加座谈会的人中,选考物理的男生和选考历史的女生分别有多少人?
参考公式:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e3821f70c08c5180e9b3086d3c9610f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/356b05e46b10ee51c3e43546d73ec96c.png)
参考数据:
0.10 | 0.05 | 0.025 | 0.010 | 0.005 | 0.001 | |
2.706 | 3.841 | 5.024 | 6.635 | 7.879 | 10.828 |
马克隆值 | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() |
重量(吨) | 0.08 | 0.12 | 0.24 | 0.32 | 0.64 | ![]() | 0.12 | 0.06 | 0.02 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/7/e2bb0132-33a9-4568-9424-bd67fb9d1bae.png?resizew=305)
(2)根据频率分布直方图,估计样本的马克隆值的众数及中位数;
(3)根据马克隆值可将棉花分为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
马克隆值 | ![]() | ![]() ![]() | 3.4以下 |
级别 | ![]() | ![]() | ![]() |
价格(万元/吨) | 1.5 | 1.4 | 1.3 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf67b30054aed292672f42db10675f99.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/551e8c4da71bebcd7f670cd4e2b984e4.png)
时长 | 2小时以内 | 2~3小时 | 3小时以上 |
频率 | 0.4 | 0.3 | 0.3 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b2a698891d42c70b597f0da4f215f09.png)
现对该市“日均使用智能手机时长与年龄的关系”进行调查,采用随机抽样的方法,抽取一个容量为200的样本,请你根据上面提供的数据.
(Ⅰ)补全下列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b72fcdc709e77910cd36a26369648b3.png)
青年人 | 非青年人 | 合计 | |
频繁使用人群 | |||
非频繁使用人群 | |||
合计 |
附:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3bc485c58dbd6e50bfb352030f4a1c42.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/356b05e46b10ee51c3e43546d73ec96c.png)
以参考数据:独立性检验界值表
0.15 | 0.10 | 0.050 | 0.025 | 0.010 | |
2.072 | 2.706 | 3.841 | 5.024 | 6.635 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5dec6404c3324aaf0004c1c269c595bd.png)
A.![]() | B.![]() | C.![]() | D.![]() |