概车纶与款理统外 则随机变量之和的标准化变量 .-EEx. x-24: Z =k=l k=1 g B. 的分布函数F,(x)对于任意x满足 2x-24 lim F(x)=lim P每 ≤X 则随机变量之和的标准化变量             − =    = = = n k k n k k n k k n D X X E X Z 1 1 1 n n k k n k k B X  = = − = 1 1  的分布函数Fn (x)对于任意x满足                − =   = = → → x B X F x P n n k k n k k n n n 1 1 lim ( ) lim  − − = = x t e dt (x). 2π 1 2 2 