名校
解题方法
1 . 习近平总书记指出:在扶贫的路上,不能落下一个贫困家庭,丢下一个贫困群众,根据相关统计,
年以后中国贫困人口规模呈逐年下降趋势,
年
年全国农村贫用发生的散点图如下:
分别对应年份
年
年.
(1)求
关于
的回归直线方程(系数精确到
):
(2)已知某贫困地区的农民人均年纯收入
(单位:万元)满足正态分布
,若该地区约有
的农民人均纯收入高于该地区最低人均年纯收入标准,则该地区最低人均年纯收入标准大约为多少万元?
参考数据与公式:
,
.
回归直线
的斜率和截距的最小二乘估计分别为
、
.
若随机变量
服从正态分布
,则
,
,
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb8b5f0ffe0a3eec01f91f2e9a5db687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d37eae8a3cf8ef8a44162c82a7229a6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae716117d0a4bea5df19be451fe6a23d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/011c386c454c08386305ee1e03d6d651.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d37eae8a3cf8ef8a44162c82a7229a6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae716117d0a4bea5df19be451fe6a23d.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e2c4d12b3a705daab723ab243b6cc88.png)
(2)已知某贫困地区的农民人均年纯收入
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b42af60e27ceb2d1aeb1a4f6fcc371a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d74263515a0f5c89abe56d4ce6f72a5.png)
参考数据与公式:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5232b506e9e11058e0bf155c9e9e688a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/537b23541ccf855d4b0130276225cce4.png)
回归直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa0ffdf361285b7b3bca3f223bccb4fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2520e11c0417f52e24c4984e09ce787c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99895924d9aeddd89f705830acab5ad9.png)
若随机变量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29bcc248a7770a16fa10fc4602d71e0e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2131234c49c9399541019d1f1b6678fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dae4d0004b092e9fb452833928a6f60.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/600672f1b0783e0a87e0edf57a9632a2.png)
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2021-05-28更新
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4卷引用:海南省2020-2021学年高二下学期期末考试数学试题