当Y=n(n=2,3,…)时,X的条件分布 律为 P(X=mY=n)= P(X=m,Y=n P(r=n p(I-p (n-1)p2(1-p)n m=1.2..n-1律为 ( ) ( , ) ( ) P Y n P X m Y n P X m Y n = = = = = = m =1,2,,n −1 1 1 ( 1) (1 ) (1 ) 2 2 2 2 − = − − − = − − n p p n p p n n 当Y = n (n = 2,3,) 时, X 的条件分布