解题方法
1 . 某连锁便利店从
年到
年销售商品品种为
种,从
年开始,该便利店进行了全面升级,销售商品品种为
种.下表中列出了从
年到
年的利润额.
(1)若某年的利润额超过
万元,则该便利店当年会被评选为示范店;若利润额不超过
万元,则该便利店当年不会被评选为示范店.试完成
列联表,并判断商品品种数量与便利店是否为示范店有关?(显著性水平
,
)
(2)请根据
年至
年(剔除
年的数据)的数据建立
与
的线性回归模型①;根据
年至
年的数据建立
与
的线性回归模型②.分别用这两个模型,预测
年该便利店的利润额并说明这样的预测值是否可靠?(回归系数精确到
,利润精确到
万元)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/442470e2e4b15229eefd5c2b19d01932.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6567511bb9486b2ca7452b870abd2a1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4abb59695562b3a1295a251dc97da700.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4f95463e4696bcb6ed28581bad689d0c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cfce2106c9ad85e4965af5d95c9bf4d8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/442470e2e4b15229eefd5c2b19d01932.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e946baf1316ac1f219398ecedadf6cf.png)
年份 | ||||||||||
利润额
|
(1)若某年的利润额超过
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae4e4c36a1ec6021c9056d8a05bafd34.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae4e4c36a1ec6021c9056d8a05bafd34.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b72fcdc709e77910cd36a26369648b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ead9d6ff51996f3ebace6f212e11a9e4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a93888a85455e51d2f0d21e34263d7b5.png)
品种为 | 品种为 | 总计 | |
被评为示范店次数 | |||
未被评为示范店次数 | |||
总计 |
(2)请根据
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/442470e2e4b15229eefd5c2b19d01932.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e946baf1316ac1f219398ecedadf6cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d01dd350dc95f42f1883e0cc7aae084.png)
![](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/4f95463e4696bcb6ed28581bad689d0c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e946baf1316ac1f219398ecedadf6cf.png)
![](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/a8e8936c9fe1e81726455908657a29fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/042e234d538bc2c789d7c5a314f1ca92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a87796ee30e6c5d5e6b6285b32abe10c.png)
回归系数与
的公式如下:
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