·Y的随机抽取的n组样本观测值的联合概率 L(B,o)=P(y1,y2,.,yn) 1 220-a+av+++房.w》 e (2π)σ 2(Y-XB)'(Y-B) (2π)2o0 • Y的随机抽取的n组样本观测值的联合概率 L P y y y e e n n y x x x n n i i i k ki n (  , ) ( , , , ) ( ) ( ) ( (     )) (  ) (  )                     2 1 2 1 2 1 2 1 2 1 2 2 2 0 1 1 2 2 2 2 2 = = = − − + + + + − −  −   Y X Y X