6.
下图是我国\(2008\)年至\(2014\)年生活垃圾无害化处理量\((\)单位:亿吨\()\)的折线图
\((1)\)由折线图看出,可用线性回归模型拟合\(y\)与\(t\)的关系,请用相关系数\(r\)加以说明;
\((2)\)建立\(y\)关于\(t\)的回归方程\((\)系数精确到\(0.01)\),预测\(2016\)年我国生活垃圾无害化处理量.
附注:参考数据:\(\sum\limits_{i=1}^{n}{\left( {{t}_{i}}-\overline{t} \right)\left( {{y}_{i}}-\overline{y} \right)}{=}2.89\),\(\sqrt{\sum\limits_{i=1}^{7}{{{\left( {{y}_{i}}-\overline{y} \right)}^{2}}}}=0.55\),\(\sqrt{7}\approx 2.646\).
参考公式: 回归方程\(\widehat{y}=\widehat{a}+\widehat{b}t\)中斜率和截距的最小二乘估计公式分别为:\(\widehat{a}{=}\overline{y}-\widehat{b}\overline{t}\),
\(\widehat{b}=\dfrac{\sum\limits_{i=1}^{n}{\left( {{t}_{i}}-\overline{t} \right)\left( {{y}_{i}}-\overline{y} \right)}}{\sum\limits_{i=1}^{n}{{{\left( {{t}_{i}}-\overline{t} \right)}^{2}}}}\) ; 相关系数\(r=\dfrac{\sum\limits_{i=1}^{n}{\left( {{t}_{i}}-\overline{t} \right)\left( {{y}_{i}}-\overline{y} \right)}}{\sqrt{\sum\limits_{i=1}^{n}{{{\left( {{t}_{i}}-\overline{t} \right)}^{2}}\sum\limits_{i=1}^{n}{{{\left( {{y}_{i}}-\overline{y} \right)}^{2}}}}}}\).