2.
某公司为了确定下一年度投入某种产品的宣传费,需要了解年宣传费\(x(\)单位:万元\()\),对年销售量\(y(\)单位:\(t)\)和年利润\(z(\)万元\()\)的影响,为此,该公司对近\(7\)年宣传费\(x_{i}\)和年销售量\(y_{i}=(i=1,2,…,7)\)的数据进行了初步处理,得到了如图所示的散点图和表中的统计量的值.
![](https://www.ebk.net.cn/tikuimages/2/2018/600/shoutiniao56/e95d1cf471bc42d252361a068101faf9.png)
\(\overline{x}\) | \(\overline{y}\) | \(\overline{k}\) | \(\sum\limits_{i=1}^{7}{(}{{x}_{i}}-\overline{x}{{)}^{2}}\) | \(\sum\limits_{i=1}^{7}{(}{{k}_{i}}-\overline{k}{{)}^{2}}\) | \(\sum\limits_{i=1}^{7}{(}{{x}_{i}}-\overline{x})({{y}_{i}}-\overline{y})\) | \(\sum\limits_{i=1}^{7}{(}{{x}_{i}}-\overline{x})({{k}_{i}}-\overline{k})\) |
\(17.40\) | \(82.30\) | \(3.6\) | \(140\) | \(9.7\) | \(2935.1\) | \(35.0\) |
其中\(k_{i}=\ln y_{i}\),\(\overline{k}=\dfrac{1}{7}\sum\limits_{i=1}^{7}{{{k}_{i}}}\).
\((\)Ⅰ\()\)根据散点图判断,\(y=bx+a\)与\(y={{c}_{1}}{{e}^{{{c}_{2}}x}}\)哪一个更适宜作为年销售量\(y\)关于年宣传费\(x\)的回归方程类型?\((\)给出判断即可,不必说明理由\()\)
\((\)Ⅱ\()\)根据\((\)Ⅰ\()\)的判断结果及表中数据,建立\(y\)关于\(x\)的回归方程;
\((\)Ⅲ\()\)已知这种产品年利润\(z\)与\(x\),\(y\)的关系为\(z=e^{-2.5}y-0.1x+10\),当年宣传费为\(28\)万元时,年销售量量及年利润的预报值分别是多少?
附:\(①\)对于一组具有有线性相关关系的数据\((μ_{i},v_{i})(i=1,2,3,…,n)\),其回归直线\(v=βu+α\)的斜率和截距的最小二乘估计分别为\(\widehat{\beta }=\dfrac{\sum\limits_{i=1}^{n}{(}{{u}_{i}}-\overline{u})({{v}_{i}}-\overline{v})}{\sum\limits_{i=1}^{n}{(}{{u}_{i}}-\overline{u}{{)}^{2}}}\),\(\widehat{\alpha }=\overline{v}-\widehat{\beta }\overline{u}\)
\(②\)
\(e^{-2.5}\) | \(e^{0.75}\) | \(e\) | \(e^{3}\) | \(e^{7}\) |
\(0.08\) | \(0.47\) | \(2.72\) | \(20.09\) | \(1096.63\) |