9.
已知数组\((x_{1},y_{1})\),\((x_{2},y_{2})\),\(…\),\((x_{10},y_{10})\)满足线性回归方程\( \hat y=bx+a\),则“\((x_{0},y_{0})\)满足线性回归方程\( \hat y=bx+a\)”是“\(x_{0}= \dfrac {x_{1}+x_{2}+…+x_{10}}{10}\),\(y_{0}= \dfrac {y_{1}+y_{2}+…+y_{10}}{10}\)”的 ______ \(.\)条件\(.(\)填充分不必要、必要不充分、充要\()\)