![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/10/6002d8ed-1b35-44d3-8642-7c021567883f.png?resizew=288)
A.0 | B.1 | C.16 | D.32 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/132de9682ce9a412b7b517aa209726ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a6c6e7c025362c46a64a8956761f08e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8697ff4a2a718027ddb82530785893f2.png)
![](https://img.xkw.com/dksih/QBM/2018/3/26/1910596015235072/1913413237334016/STEM/32ab2de56add41008315939648737f3c.png?resizew=132)
A.![]() | B.![]() | C.![]() | D.![]() |
3 . 在党的十九大报告中,习近平总书记提出“绿水青山就是金山银山”;为响应总书记的号召,某市旅游局计划共投入4千万元,对全市各旅区的环境进行综合治理,并且对各放游量区收益的增加值作了初步的估计,根据旅游局的治理规划方案,针对各旅游景区在治理后收益的增加值,工作人员绘了下面的频率分布直方图(如图所示),由于操作失误,横轴的数据丢失,但可以确定横轴是从0开始计数的.
(I)频率分布直方图中各小长方形的宽度相等,求这个宽度;
(II)旅游局在投入4千万元的治理经费下,估计全市旅游景区收量增加值的平均数为多少万元(以各组的区间中点值代表该组的取值)
(III)若旅游局投入的不同数额的经费,按照以上的研究方法,得到以下数据:
投入治理经费x(单位:千万元) | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
收益的增加值y(单位:万元) | 2 | 3 | 2 | 7 | 7 | 9 |
请将(II)的答案填入上表的空白栏,结果显示x与y之间存在线性相关关系.在优化环境的同时,旅游局还计划使全市旅游景区收益的总额至少增加10万元,试估计旅游局应该对全市旅游景区至少投入多少千万元的治理经费?(答案精确到0.01)
附注:回归直线方程中的斜率和截距的最小二乘法估计公式分别为:
,
.
![](https://img.xkw.com/dksih/QBM/2018/3/22/1907351951048704/1908857626968064/STEM/61561827-7f08-488b-a5ba-6fe86c495e3e.png?resizew=244)
A.![]() ![]() | B.![]() ![]() |
C.![]() ![]() | D.![]() ![]() |
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b30d8c4195ad16c020f894b6c2249584.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91e07104b699c4012be2d26160976a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8860d9787671b53b1ab68b3d526f5ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91e07104b699c4012be2d26160976a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7766c61780fb461cb5730ad04fc0a525.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c6ead586de1fea336c803d73cf874b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/259af9aa7b4e8a2314e11399c28e2446.png)
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![](https://img.xkw.com/dksih/QBM/2018/8/22/2015821013377024/2017450469195776/STEM/b4524f8a57b04ac6af44965d7529f4bd.png?resizew=297)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
(2)用分层抽样的方法从这
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90dd550e1ad9bbf01687ffb4aab788ec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06fc7811f9525e8b8c833746d6af5c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91e07104b699c4012be2d26160976a2.png)
(3)现从(2)中完成年度任务的销售员中随机选取
![](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/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
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A.![]() | B.![]() | C.![]() | D.![]() |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14d21726b82e52bbd091c3d3279ba584.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/20/65eb6803-5044-4469-bd8a-ec98b2a0007c.png?resizew=429)
A.2 | B.-1 | C.![]() | D.![]() |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb6bfefa5b41faae17987876d570685d.png)
![](https://img.xkw.com/dksih/QBM/2017/3/30/1654874020233216/1654909180067840/STEM/d43dab5882f94b8c96109414d9507d24.png?resizew=448)
![](https://img.xkw.com/dksih/QBM/2017/3/30/1654874020233216/1654909180067840/STEM/04a021a944bd445088ead0c3faad7463.png?resizew=399)
(1)请根据样本估算该校男生平均每天足球运动的时间(结果精确到0.1);
(2)若称平均每天足球运动的时间不少于2小时的学生为“足球健将”,低于2小时的学生为“非足球健将”.
①请根据上述表格中的统计数据填写下面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b72fcdc709e77910cd36a26369648b3.png)
![](https://img.xkw.com/dksih/QBM/2017/3/30/1654874020233216/1654909180067840/STEM/d709996ddfab4aee9775ec5ecc13e2d6.png?resizew=369)
②若在足球运动时间不足1小时的男生中抽取2名代表了解情况,求这2名代表都是足球运动时间不足半小时的概率.
参考公式:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63501b254962e1190b092bbf4a568027.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/356b05e46b10ee51c3e43546d73ec96c.png)
参考数据:
![]() | 0.05 | 0.40 | 0.25 | 0.15 | 0.10 | 0.05 | 0.025 | 0.010 |
![]() | 3.841 | 0.708 | 1.323 | 2.072 | 2.706 | 3.841 | 5.024 | 6.635 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://img.xkw.com/dksih/QBM/2017/3/30/1654874020233216/1654909179674624/STEM/75aed7b105eb4e259619bac21222510e.png?resizew=194)
A.16 | B.32 | C.64 | D.1024 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4799efe552362da99b08fa6f48e54000.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c21fb526b9f5ae5181b84b61b6adb458.png)
A.![]() | B.![]() | C.![]() | D.![]() |