(2)我们规定得分80分以上(含80分)的为“优秀”,低于80分的为“非优秀”.
优秀人数 | 非优秀人数 | 合计 | |
强化训练前 | |||
强化训练后 | |||
合计 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b253ec362b46012c30d1eb2d3030ee2a.png)
附:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/776d32c5963be22b0fe71ddd0248c7cb.png)
0.05 | 0.010 | 0.005 | 0.001 | |
3.841 | 6.635 | 7.879 | 10.828 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b72fcdc709e77910cd36a26369648b3.png)
更关注保暖性能 | 更关注款式设计 | 合计 | |
女性 | 160 | 80 | 240 |
男性 | 120 | 40 | 160 |
合计 | 280 | 120 | 400 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e3821f70c08c5180e9b3086d3c9610f.png)
![]() | 0.10 | 0.05 | 0.010 |
![]() | 2.706 | 3.841 | 6.635 |
(2)若从被调查的更关注保暖性能的人中按男女比例用分层抽样的方法抽取7人进行采访,再从这7人中任选2人赠送羽绒服,求这2人都是女性的概率.
(1)完成下面的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b72fcdc709e77910cd36a26369648b3.png)
爱好足球 | 不爱好足球 | 总计 | |
男生 | |||
女生 | |||
总计 |
(2)判断能否有
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc3e36a8ddec055b2164ae365daf1326.png)
附:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f8ec200973736ac8bcd9aa633855d93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/356b05e46b10ee51c3e43546d73ec96c.png)
![]() | 0.10 | 0.05 | 0.01 | 0.001 |
![]() | 2.706 | 3.841 | 6.635 | 10.828 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a142765f29499673b40e26ce4f1d36d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d27b00644365909601ed84ff49813d5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e19eb06f4d72f09820825ccd49c31b72.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/328fcb58a789bd05648864910ede4d36.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf3ea74afcb17a3c5f6d00f21d6e2d50.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/11/1ae4020d-26d9-446e-b0d5-103d142ce4d2.png?resizew=233)
(1)估计这100名学生的竞赛成绩的中位数(结果保留整数);
(2)在抽取的100名学生中,规定:竞赛成绩不低于70分为“优秀”,竞赛成绩低于70分为“非优秀”.请将下面的2×2列联表补充完整,并判断是否有99%的把握认为“竞赛成绩是否优秀与性别有关”?(精确到0.001)
优秀 | 非优秀 | 合计 | |
男 | 30 | ||
女 | 50 | ||
合计 | 100 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3bc485c58dbd6e50bfb352030f4a1c42.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/356b05e46b10ee51c3e43546d73ec96c.png)
0.10 | 0.05 | 0.025 | 0.010 | 0.005 | 0.001 | |
2.706 | 3.841 | 5.024 | 6.635 | 7.879 | 10.828 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2afa5a5a7eb829aa93e1fb7d7a2f64eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b72fcdc709e77910cd36a26369648b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e44d30b6ad0d96ce99230672d2a41c5f.png)
男生 | 女生 | 合计 | |
了解 | ![]() | ||
不了解 | ![]() | ||
合计 | ![]() | ![]() |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
(2)为弄清学生不了解冬季奥运会项目的原因,采用分层抽样的方法从抽取的不理解冬季奥运会项目的学生中随机抽取9人,再从这9人中抽取2人进行面对面交流,“至少抽到一名女生”的概率;
附表:
![]() | 0.10 | 0.05 | 0.025 | 0.010 | 0.001 |
![]() | 2.706 | 3.841 | 5.024 | 6.635 | 10.828 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7dc70b5e1ba847b9918a50f67bfbe8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61c478da2397882f629cd1be5f6cd58e.png)
选取的100名用户中男性用户评分情况:
得分 | ||||||
男生人数 | 7 | 11 | 18 | 12 | 8 | 8 |
得分 | ||||||
女生人数 | 3 | 9 | 12 | 8 | 2 | 2 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f58d9a123e465dace224231f54ee94e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a40cf767fd2a684f2f1ed9216836792.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f8c2a91a15e1f7b296b64d3bd2e7551.png)
(2)若用户评分分值不低于80分,则定位用户对产品满意.填写下面的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b72fcdc709e77910cd36a26369648b3.png)
男性用户 | 女性用户 | 合计 | |
对产品满意 | |||
对产品不满意 | |||
合计 | 100 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d8b4c3497b89b1522fb1d5dcd631e481.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/356b05e46b10ee51c3e43546d73ec96c.png)
0.050 | 0.025 | 0.010 | 0.005 | 0.001 | |
k | 3.841 | 5.024 | 6.635 | 7.879 | 10.828 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d5b6e2d6b9a4baaa89e803f99abb0e2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4467654a8970fa823cef7ed2bb2d9ae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee7fc133001a9e5952fbe9817821519d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/407703dcd44f98293ece43e23a99a748.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca5fca10f3524d20aa25066b9c78bbf0.png)
![](https://img.xkw.com/dksih/QBM/2022/4/15/2958566563348480/2965058287525888/STEM/c8040da3-2994-4813-a9f7-a2ca6767a912.png?resizew=189)
(1)求这100名学生中一次能做引体向上5个以下的人数.并完善频率分布直方图(即作出“引体向上个数为0~5”所对应的矩形);
(2)若男生一次能做引体向上10个或以上为及格,完成下面2×2列联表.并判断能否有99%的把握认为该学校男生“引体向上是否及格”与“所在年级”有关?
引体向上及格 | 引体向上不及格 | 总计 | |
高三男生 | 50 | ||
高二男生 | 20 | 50 | |
合计 | 100 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b2f70b01e964f4084816bd12125b714.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/356b05e46b10ee51c3e43546d73ec96c.png)
0.100 | 0.050 | 0.010 | 0.001 | |
2.706 | 3.841 | 6.635 | 10.828 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf31876698721a199c7c53c6b320aa86.png)
(1)完成下面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b72fcdc709e77910cd36a26369648b3.png)
有兴趣 | 没有兴趣 | 合计 | |
男 | |||
女 | 75 | ||
合计 | 600 |
附:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/930771d26bd463a4f80d0a1a76b36c99.png)
![]() | 0.100 | 0.050 | 0.025 | 0.010 | 0.001 |
2.706 | 3.841 | 5.024 | 6.635 | 10.828 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf31876698721a199c7c53c6b320aa86.png)
(1)完成下面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b72fcdc709e77910cd36a26369648b3.png)
有兴趣 | 没有兴趣 | 合计 | |
男 | |||
女 | 75 | ||
合计 | 600 |
附:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/930771d26bd463a4f80d0a1a76b36c99.png)
0.100 | 0.050 | 0.025 | 0.010 | 0.001 | |
2.706 | 3.841 | 5.024 | 6.635 | 10.828 |
男性观众 | 女性观众 | 合计 | |
流泪 | 20 | ||
没有流泪 | 5 | 20 | |
合计 |
(2)以分层抽样的方式,从流泪与没有流泪的观众中抽取5人,然后从这5人中再随机抽取2人,求这2人都流泪的概率.
附:
![]() | 0.100 | 0.050 | 0.010 | 0.001 |
![]() | 2.706 | 3.841 | 6.635 | 10.828 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3bc485c58dbd6e50bfb352030f4a1c42.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/356b05e46b10ee51c3e43546d73ec96c.png)