←概率论 为求条件分布,先求边缘分布 X的边缘分布律是: PX=m PX=m,Y=n n-=m+1 =∑p2(1-p)2=p2∑0-p n=m+1 n=n+1 2(1-p) m+1-2 P 1-(1-p) p(1-p) (〃=1,2,…)概率论 为求条件分布,先求边缘分布. X的边缘分布律是: ( m=1,2, … ) = + − = − 1 2 2 (1 ) n m n p p = + − = − 1 2 2 (1 ) n m n p p 1 (1 ) (1 ) 1 2 2 p p p m − − − = + − 1 (1 ) − = − m p p 1 , n m P X m P X m Y n + = + = = = =