正规方程 ∑Y=n月+B∑X ∑YX=B∑X1+B2∑X2 2021/220 Hongfeng Peng Department of 10 Finance, wuhan Univers ity2021/2/20 Hongfeng Peng Department of Finance, Wuhan University 10 正规方程 1 2 2 1 2 ˆ ˆ ˆ ˆ i i i i i i Y n X Y X X X     = + = +     