总平均x=896 依(2-1-10)式有: =x=89.6 1=x1-4-a1=90896-0.4=0 =90-896=0.4 2=x12-4-a1=92-896-0.4=2 a2=x2-x=94-896=4413=x13-4-a1=88-896-04=-2 x=95-89.6=54 这样x,就可以分解成三个数之和: X1=896+04+0 4=x4-x=85-89.6=-46 89.6+04+2 a5=x5-x=84-896=-56X13=896+04-29 _ _ _ _ 1 1 _ _ 2 2 _ _ 3 3 _ _ 4 4 _ _ 5 5 89.6 89.6 90 89.6 0.4 94 89.6 4.4 95 89.6 5.4 85 89.6 4.6 84 89.6 5.6 x x a x x a x x a x x a x x a x x        = = = = − = − = = − = − = = − = − = = − = − = − = − = − = − 总平均 11 11 1 12 12 1 13 13 1 90 89.6 0.4 0 92 89.6 0.4 2 88 89.6 0.4 2 89.6 0.4 0 89.6 0.4 2 89.6 0.4 2 ij l x a l x a l x a x          = − − = − − = = − − = − − = = − − = − − = − = + + = + + = + − 11 12 13 依(2-1-10)式有： 这样 就可以分解成三个数之和： x x x