1 . 每年的4月23日为世界读书日,为调查某高校学生(学生很多)的读书情况,随机抽取了男生,女生各20人组成的一个样本,对他们的年阅读量(单位:本)进行了统计,分析得到了男生年阅读量的频数分布表和女生年阅读量的频率分布直方图.
男生年阅读量的频数分布表(年阅读量均在区间
内)
![](https://img.xkw.com/dksih/QBM/2017/4/12/1664093626662912/1664156307513344/STEM/b815bddf27ed40cb8f5603351798f4bd.png?resizew=401)
(Ⅰ)根据女生年阅读量的频率分布直方图估计该校女生年阅读量的中位数;
![](https://img.xkw.com/dksih/QBM/2017/4/12/1664093626662912/1664156307513344/STEM/2d2d0a20ac2e4deb9a5596213680fc14.png?resizew=244)
(Ⅱ)若年不小于40本为阅读丰富,否则为阅读不丰富,依据上述样本研究年阅读量与性别的关系,完成下列
列联表,并判断是否有99%的把握认为阅读丰富与性别有关;
![](https://img.xkw.com/dksih/QBM/2017/4/12/1664093626662912/1664156307513344/STEM/88be00117eaf420982ee5e97eb3aad51.png?resizew=301)
(Ⅲ)在样本中,从年阅读量在
的学生中,随机抽取2人参加全市的征文比赛,记这2人中男生人数为
,求
的分布列和期望.
附:
,其中![](https://staticzujuan.xkw.com/quesimg/Upload/formula/356b05e46b10ee51c3e43546d73ec96c.png)
男生年阅读量的频数分布表(年阅读量均在区间
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/649540a94f05732c1b53ba21796645cd.png)
![](https://img.xkw.com/dksih/QBM/2017/4/12/1664093626662912/1664156307513344/STEM/b815bddf27ed40cb8f5603351798f4bd.png?resizew=401)
(Ⅰ)根据女生年阅读量的频率分布直方图估计该校女生年阅读量的中位数;
![](https://img.xkw.com/dksih/QBM/2017/4/12/1664093626662912/1664156307513344/STEM/2d2d0a20ac2e4deb9a5596213680fc14.png?resizew=244)
(Ⅱ)若年不小于40本为阅读丰富,否则为阅读不丰富,依据上述样本研究年阅读量与性别的关系,完成下列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b72fcdc709e77910cd36a26369648b3.png)
![](https://img.xkw.com/dksih/QBM/2017/4/12/1664093626662912/1664156307513344/STEM/88be00117eaf420982ee5e97eb3aad51.png?resizew=301)
(Ⅲ)在样本中,从年阅读量在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d14154507166882352784b9de0a36b33.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
附:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b2f70b01e964f4084816bd12125b714.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/356b05e46b10ee51c3e43546d73ec96c.png)
![](https://img.xkw.com/dksih/QBM/2017/4/12/1664093626662912/1664156307513344/STEM/ac82298652f14cd79e2cc44dcfd82e5d.png?resizew=233)
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