解题方法
1 . 某班同学利用国庆节进行社会实践,对
岁的人群随机抽取
人进行了一次生活习惯是否符合低碳观念的的调查,若生活习惯符合低碳观念的称为“低碳族”,否则称为“非低碳族”,得到如下统计表和各年龄段人数频率分布直方图:
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/10/7d2a1264-545d-4584-8b38-ac2282cbee48.png?resizew=271)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/10/f8607d2a-ab21-43dc-9d10-e2224677f3ab.png?resizew=345)
(1)补全频率分布直方图并求
的值;
(2)从
岁年龄段的“低碳族”中采用分层抽样法抽取18人参加户外低碳体验活动,其中选取3人作为领队,记选取的3名领队中年龄在
岁的人数为
,求
的分布列和期望
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d493e33681f16cefede90285d84080fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/10/7d2a1264-545d-4584-8b38-ac2282cbee48.png?resizew=271)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/10/f8607d2a-ab21-43dc-9d10-e2224677f3ab.png?resizew=345)
(1)补全频率分布直方图并求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d51e106e1556f213ac851b79a085d2bd.png)
(2)从
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64fc138be9688253cbdeae2808eb74ae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64fc138be9688253cbdeae2808eb74ae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c025fce1a29b03212bb4efdfe77bd66.png)
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2 . 从某小区抽取50户居民进行月用电量调查,发现其用电量都在50到350度之间,将用电量的数据绘制成频率分布直方图如下.
![](https://img.xkw.com/dksih/QBM/2018/4/13/1923321674727424/1924021284544512/STEM/60f9b90d3d4b45eca6793791934f3d7e.png?resizew=329)
(1)求频率分布直方图中
的值并估计这50户用户的平均用电量;
(2)若将用电量在区间
内的用户记为
类用户,标记为低用电家庭,用电量在区间
内的用户记为
类用户,标记为高用电家庭,现对这两类用户进行问卷调查,让其对供电服务进行打分,打分情况见茎叶图:
![](https://img.xkw.com/dksih/QBM/2018/4/13/1923321674727424/1924021284544512/STEM/3f5a2b37d23647d6a30ad334741a8d8f.png?resizew=362)
①从
类用户中任意抽取3户,求恰好有2户打分超过85分的概率;
②若打分超过85分视为满意,没超过85分视为不满意,请填写下面列联表,并根据列联表判断是否有
的把握认为“满意度与用电量高低有关”?
附表及公式:
,
.
![](https://img.xkw.com/dksih/QBM/2018/4/13/1923321674727424/1924021284544512/STEM/60f9b90d3d4b45eca6793791934f3d7e.png?resizew=329)
(1)求频率分布直方图中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
(2)若将用电量在区间
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/27021654e26c879b0ca067e14425ff63.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bd912af5e2a64028abe0ef1e2dfe604.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://img.xkw.com/dksih/QBM/2018/4/13/1923321674727424/1924021284544512/STEM/3f5a2b37d23647d6a30ad334741a8d8f.png?resizew=362)
①从
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
②若打分超过85分视为满意,没超过85分视为不满意,请填写下面列联表,并根据列联表判断是否有
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b399e6815afcaa24f2889e58c79c10a1.png)
满意 | 不满意 | 合计 | |
![]() | |||
![]() | |||
合计 |
附表及公式:
![]() | 0.050 | 0.010 | 0.001 |
![]() | 3.841 | 6.635 | 10.828 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3bc485c58dbd6e50bfb352030f4a1c42.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/356b05e46b10ee51c3e43546d73ec96c.png)
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2018-04-14更新
|
904次组卷
|
6卷引用:海南省2018届高三第二次联合考试数学理试题
名校
3 . 如图,网格纸上正方形小格的边长为
,粗线画出的是某几何体的三视图,则该几何体的最长棱的长度为( )
![](https://img.xkw.com/dksih/QBM/2018/5/25/1952843769282560/2009099459461120/STEM/38639cab-402a-456f-81f6-8ff4d0142dcc.png?resizew=253)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://img.xkw.com/dksih/QBM/2018/5/25/1952843769282560/2009099459461120/STEM/38639cab-402a-456f-81f6-8ff4d0142dcc.png?resizew=253)
A.9 | B.8 | C.![]() | D.![]() |
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2018-08-12更新
|
465次组卷
|
6卷引用:海南省2018届高三阶段性测试(二模)数学文试题
4 . 如图所示,网格纸上小正方形的边长为1,粗线画出的是某几何体的三视图,则该几何体的体积为
![](https://img.xkw.com/dksih/QBM/2018/5/7/1940175563456512/1941716220846080/STEM/1d2865af564b4ad4bd3d374af9cd95fd.png?resizew=150)
![](https://img.xkw.com/dksih/QBM/2018/5/7/1940175563456512/1941716220846080/STEM/1d2865af564b4ad4bd3d374af9cd95fd.png?resizew=150)
A.![]() | B.![]() | C.![]() | D.![]() |
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5 . 如图,网格纸上小正方形的边长为1,粗线画出的是某个几何的三视图,则该几何体的体积为
![](https://img.xkw.com/dksih/QBM/2016/6/22/1572778187038720/1572778192871424/STEM/d35084e232ae4fd59df2dfea3eb83c32.png)
![](https://img.xkw.com/dksih/QBM/2016/6/22/1572778187038720/1572778192871424/STEM/d35084e232ae4fd59df2dfea3eb83c32.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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2018-03-08更新
|
218次组卷
|
2卷引用:2016届海南省海口一中高三高考模拟三文科数学试卷
2011·海南海口·一模
6 . 如图,点
是椭圆
上一动点,点
是点
在
轴上的射影,坐标平面
内动点
满足:
(
为坐标原点),设动点
的轨迹为曲线
.
![](https://img.xkw.com/dksih/QBM/2011/5/20/1570213308317696/1570213313871872/STEM/5aa8bfdbe9fe4cb28e5da6be57f9e72e.png?resizew=206)
(Ⅰ)求曲线
的方程并画出草图;
(Ⅱ)过右焦点
的直线
交曲线
于
,
两点,且
,点
关于
轴的对称点为
,求直线
的方程.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6cae00bdc6f8b564b6b15b32572c848b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ee31829d0d4d5f779a957d7df8058ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25c70b7429573e10797d12d564c05099.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://img.xkw.com/dksih/QBM/2011/5/20/1570213308317696/1570213313871872/STEM/5aa8bfdbe9fe4cb28e5da6be57f9e72e.png?resizew=206)
(Ⅰ)求曲线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
(Ⅱ)过右焦点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d7bfbd4e1cd5349db7884c65c23b239.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce8f887360a533f0a25b0b34fb11f0a1.png)
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7 . 如图,网格纸上小正方形的边长为1,粗线画出的是某个几何体的三视图,则该几何体的体积为
![](https://img.xkw.com/dksih/QBM/2016/6/22/1572779326636032/1572779332648960/STEM/8879fad976d14d7b9795b2faadf9d11f.png)
![](https://img.xkw.com/dksih/QBM/2016/6/22/1572779326636032/1572779332648960/STEM/8879fad976d14d7b9795b2faadf9d11f.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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2011·海南海口·一模
8 . 某市为了对学生的数理(数学与物理)学习能力进行分析,从10000名学生中随机抽出100位学生的数理综合学习能力等级分数(6分制)作为样本,分数频数分布如下表:
(Ⅰ)如果以能力等级分数大于4分作为良好的标准,从样本中任意抽取2名学生,求恰有1名学生为良好的概率;
(Ⅱ)统计方法中,同一组数据常用该组区间的中点值(例如区间
的中点值为1.5)作为代表:
(ⅰ)据此,计算这100名学生数理学习能力等级分数的期望
及标准差
(精确到0.1);
(ⅱ) 若总体服从正态分布,以样本估计总体,估计该市这10000名学生中数理学习能力等级在
范围内的人数 .
(Ⅲ)从这10000名学生中任意抽取5名同学,他们数学与物理单科学习能力等级分数如下表:
![](https://img.xkw.com/dksih/QBM/2011/5/19/1570211052109824/1570211057737728/STEM/146b833402a94ea28cba219e071638b7.png?resizew=220)
(ⅰ)请画出上表数据的散点图;
(ⅱ)请根据上表提供的数据,用最小二乘法求出
关于
的线性回归方程
.(附参考数据:
)
等级得分 | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() |
人数 | 3 | 17 | 30 | 30 | 17 | 3 |
(Ⅱ)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/2f69466c14b9b6caa024f9b1e101cad9.png)
(ⅰ)据此,计算这100名学生数理学习能力等级分数的期望
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1100379a4385b9ce064847bc21760adc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c0ad7e7853a069537387b5192f73844.png)
(ⅱ) 若总体服从正态分布,以样本估计总体,估计该市这10000名学生中数理学习能力等级在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f79a7e7f0bc2abb898d56467f4c968ca.png)
(Ⅲ)从这10000名学生中任意抽取5名同学,他们数学与物理单科学习能力等级分数如下表:
![](https://img.xkw.com/dksih/QBM/2011/5/19/1570211052109824/1570211057737728/STEM/92c842354cba440fbafadd717816c31f.png?resizew=219)
![](https://img.xkw.com/dksih/QBM/2011/5/19/1570211052109824/1570211057737728/STEM/146b833402a94ea28cba219e071638b7.png?resizew=220)
(ⅰ)请画出上表数据的散点图;
(ⅱ)请根据上表提供的数据,用最小二乘法求出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bcecfbd0e0b460f4e4ff6f654bd4608.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b919f08c2b263a69b57ec6b10d94f57.png)
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