名校
解题方法
1 . 某公司研发了一种帮助家长解决孩子早教问题的萌宠机器人.萌宠机器人语音功能让它就像孩子的小伙伴一样和孩子交流,记忆功能还可以记住宝宝的使用习惯,很快找到宝宝想听的内容.同时提供快乐儿歌、国学经典、启蒙英语等早期教育内容,且云端内容可以持续更新.萌宠机器人一投放市场就受到了很多家长欢迎.为了更好地服务广大家长,该公司研究部门从流水线上随机抽取
件萌宠机器人(以下简称产品),统计其性能指数并绘制频率分布直方图(如图
):
![](https://img.xkw.com/dksih/QBM/2022/4/22/2963830638542848/2965840985235456/STEM/6420c21f-c1f7-47bc-989d-d704828ca550.png?resizew=241)
![](https://img.xkw.com/dksih/QBM/2022/4/22/2963830638542848/2965840985235456/STEM/7d37f933-16c6-49f3-bad6-83e15fc53b8a.png?resizew=143)
(1)求性能指数的众数与中位数;
(2)该公司为了解年营销费用
(单位:万元)对年销售量
(单位:万件)的影响,对近
年的年营销费用
,和年销售量
数据做了初步处理,得到的散点图(如图
)及一些统计量的值.
表中
,
,
,
.
根据散点图判断,
可以作为年销售量
(万件)关于年营销费用
(万元)的回归方程.
(i)求
关于
的回归方程;(取
)
(ii)按经验可知,若营销费为
(万元)则会产生成本
(万元),若每件产品的销售利润为
元,用所求的回归方程估计该公司应投入多少营销费,才能使得该产品一年的收益达到最大?(收益
营销利润
成本).
参考公式:对于一组数据
,
,
,
,其回归直线
的斜率和截距的最小二乘估计分别为
,
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0efba7147f5b9ced8bc4a72f0a9fb8af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://img.xkw.com/dksih/QBM/2022/4/22/2963830638542848/2965840985235456/STEM/6420c21f-c1f7-47bc-989d-d704828ca550.png?resizew=241)
![](https://img.xkw.com/dksih/QBM/2022/4/22/2963830638542848/2965840985235456/STEM/7d37f933-16c6-49f3-bad6-83e15fc53b8a.png?resizew=143)
(1)求性能指数的众数与中位数;
(2)该公司为了解年营销费用
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91e07104b699c4012be2d26160976a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97ea8f47d8d8d9e1832d52b1c7425450.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8e44f9908e42b5a5b1838fc20969704.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
16.30 | 24.87 | 0.41 | 1.64 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90229c4f76db5de308cf8d5fc382099b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53c26fa1e573812fab6a173a4eb0ed38.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e0c311fc644b7c09c3dbdfbb3bc35bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c1697fa54776dc8a5a6135c4ebe26fe.png)
根据散点图判断,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fea788ae8bd9c0cc3924d1d051d3363c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
(i)求
![](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/e2b8534e7a0935ce47cb5f5e98c733fc.png)
(ii)按经验可知,若营销费为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/143aca2ea7b880e70eb3ecaedc5f9c50.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6706fe00b4e231e62d9ecbec567d526b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bfc339cf6dd66599db64fa3fa44e608.png)
参考公式:对于一组数据
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaf1c6aadc0129bf86f4fff9dcfb924b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/154100371e025fffe0ffae8be9567383.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daa5e9bd516f6282483b92cfe6074623.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a14e40329de36fc4a1a3f8fbfafda12.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0943f70585435955d528325e51ef013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73994f877b2173c73ace7886ca4acbb8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e1257b488abe839b85e39fa18363761.png)
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