共50条信息
在一组样本数据\((x\)\(i\),\(y\)\(i\)\()(x\)\(2\),\(y\)\(2\)\()\),\(...(x\)\(n\),\(y\)\(n\)\()\) \((n\geqslant 2,x\)\(1\),\(x\)\(2\),\(...x\)\(n\)不全相等\()\)的散点图中,若所有样本点\((x\)\(i\),\(y\)\(i\)\()(i=1\),\(2\),\(...\),\(n)\)都在直线\(y=-\dfrac{1}{3}x+1\)上,则这组样本数据的样本相关系数为\((\) \()\)
设\((\)\(x\)\({\,\!}_{1}\),\(y\)\({\,\!}_{1})\),\((\)\(x\)\({\,\!}_{2}\),\(y\)\({\,\!}_{2})\),\(…(\)\(x_{n}\),\(y_{n}\)\()\)是变量\(x\),和\(y\)的\(n\)个样本点,直线\(l\)是由这些样本点通过最小二乘法得到的线性回归方程\((\)如图\()\),则下列结论中正确的是( )
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