1 . 某超市计划按月订购一种酸奶,每天进货量相同,进货成本每瓶4元,售价每瓶6元,未售出的酸奶降价处理,以每瓶2元的价格当天全部处理完.根据往年销售经验,每天需求量与当天最高气温(单位:℃)有关.如果最高气温不低于25,需求量为500瓶;如果最高气温位于区间[20,25),需求量为300瓶;如果最高气温低于20,需求量为200瓶.为了确定六月份的订购计划,统计了前三年六月份各天的最高气温数据,得下面的频数分布表:
最高气温 | [10,15) | [15,20) | [20,25) | [25,30) | [30,35) | [35,40) |
天数 | 2 | 16 | 36 | 25 | 7 | 4 |
以最高气温位于各区间的频率估计最高气温位于该区间的概率.
(1)求六月份这种酸奶一天的需求量不超过300瓶的概率;
(2)设六月份一天销售这种酸奶的利润为Y(单位:元),当六月份这种酸奶一天的进货量为450瓶时,写出Y的所有可能值,并估计Y大于零的概率.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/254085ae2868cb0371a3844cac3fd14d.png)
最高 气温 | [10, 15) | [15, 20) | [20, 25) | [25, 30) | [30, 35) | [35, 40) |
天数 | 2 | 16 | 36 | 25 | 7 | 4 |
(1)求六月份这种酸奶一天的需求量X(单位:瓶)的分布列.
(2)设六月份一天销售这种酸奶的利润为Y(单位:元),当六月份这种酸奶一天的进货量n(单位:瓶)为多少时,Y的数学期望达到最大值?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9c214cc074cf24aa90f2dfb01de102a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3dac5b023be85dcb00653ccd2eca13f.png)
(1)一顾客购买了20个该果园的“糖心苹果”,求会买到果径小于56
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9c214cc074cf24aa90f2dfb01de102a.png)
(2)为了提高利润,该果园每年投入一定的资金,对种植、采摘、包装、宣传等环节进行改进.如图是2009年至2018年,该果园每年的投资金额
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/16/0aa58fca-9433-4abd-8983-138462093357.png?resizew=274)
该果园为了预测2019年投资金额为20万元时的年利润增量,建立了
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
模型①:由最小二乘公式可求得
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a1d7987a5a81dcf97e0c6f9b73c0605.png)
模型②:由图中样本点的分布,可以认为样本点集中在曲线:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb0027a0822fb984dc68429182c49b72.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7ae9d60c249c43595f349d5a092f63f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6970f0219fc7100665928d5f6276de04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b451952d620114e3d55afa4089e3ecc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2e5d1c33f57f4128b284b9e75f9d698.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91bb20dfa498ca6f38e7ac30ac17e21.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0451386b105094c7a459f8babf3bbad5.png)
(I)根据所给的统计量,求模型②中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
(II)根据下列表格中的数据,比较两种模型的相关指数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c85067c53e936ef32da818efe04bdbb.png)
回归模型 | 模型① | 模型② |
回归方程 | ![]() | ![]() |
![]() | 102.28 | 36.19 |
附:若随机变量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08efacb7ec7069dafde79d6e13d0fdc2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89215ea24f10b24d7ea83ae6d1f89184.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/467cf09764d3548ed791fdee25075959.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/226d2b52caa031a2fa9db35ad1f552a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b33d9063c19ee881cb6be51fe6b83766.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fa16fa102e7d1186183a93447575199.png)
相关指数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eddbd6ca2ea4ab97dd634ac17c653098.png)
参考数据:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c895bb4bf49ee9b0023e63444bf06a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8941d8b8279d833fb53c58bb838dbf5c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0591d9f78b4f4f78c5bd6baaa602ae0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3616e69114889d5d02099b6598a57136.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
该果园为了预测2019年投资金额为20万元时的年利润增量,建立了
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
模型①:由最小二乘公式可求得
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a1d7987a5a81dcf97e0c6f9b73c0605.png)
模型②:由图中样本点的分布,可以认为样本点集中在曲线:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb0027a0822fb984dc68429182c49b72.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7ae9d60c249c43595f349d5a092f63f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6970f0219fc7100665928d5f6276de04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb3479bf61fd4d649f2e584d3a5eaf5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6c17ab8a0c633a06a3b2ed8fc6e9305.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0934a8b7d6938ca0630ebeac4da3e845.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea3cd147c347806020c8736a168af621.png)
![](https://img.xkw.com/dksih/QBM/2020/3/17/2421471948890112/2422716055887872/STEM/80fc77da266a46e5b5444930c8227ab7.png?resizew=355)
(1)根据所给的统计量,求模型②中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
(2)分别利用这两个回归模型,预测投资金额为20万元时的年利润增量(结果保留两位小数);
(3)根据下列表格中的数据,比较两种模型的相关指数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c85067c53e936ef32da818efe04bdbb.png)
回归模型 | 模型① | 模型② |
回归方程 | ||
102.28 | 36.19 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/226d2b52caa031a2fa9db35ad1f552a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b33d9063c19ee881cb6be51fe6b83766.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fa16fa102e7d1186183a93447575199.png)
相关指数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5e94f8a8319781aa88a757943151be6.png)
参考数据:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0591d9f78b4f4f78c5bd6baaa602ae0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3616e69114889d5d02099b6598a57136.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/20/e3220e39-81dc-4c1b-87b7-d06b5e00cb6c.png?resizew=337)
(1)计算该样本的平均值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfbe7f95b5d89f9409ec24536da9e826.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/671f43c79d612c93a6d160335e86e177.png)
(2)根据长期生产经验,可以认为这台设备在正常状态下生产的产品的质量指标值服从正态分布
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e84c2c26cbb6b22a415fd0830401aeac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1100379a4385b9ce064847bc21760adc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/742d3e642d52e01899f66df411100838.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/671f43c79d612c93a6d160335e86e177.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d8a7c465208823b875b0a9d0b145c40.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e07ca22b8f74dacdb64c621a0648ad0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c30fd4c57b7ae86c78e6214b47104cfb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
(i)用样本估计总体,问该工厂一天生产的产品中不合格品是否超过
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/085e2252d6a912b02bd23115f0cb4fca.png)
(ii)某公司向该工厂推出以旧换新活动,补足50万元即可用设备
![](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/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/583f326b66bf3d3652bb1cabd96467b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/100251088709a6b7c0257cc03e7c42d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/356dd6809a78dacc01ab21226c4afc49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
参考数据:①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dfabf2bd8ed23270369e69d44b421a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/613a8908371b014a8584f42839cc88af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5b77b9ab66e9df270ea484a5ab1e4ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8670f93c497fc9b62dfbf36bb14aa876.png)