数理统计 统计量的观察值 : ∑(x;-x)2 n i=1 n ∑(x1-x)2;ak ∑xk=1,2, n b, ∑(x1-x)k=1,2 n-1数理统计 统计量的观察值   ( ) 1,2, 1 1 1,2, 1 ( ) ; 1 1 ( ) 1 1 ; 1 1 1 1 2 1 2 1 2  − = − =  −  =  = − =  − − =  = = = = = = x x k n b x k n x x n s x x n x s n x n i k k i n i k k i n i i n i i n i i