29.设随机变量(X Y)的分布律为-|||-x .-1 0 1-|||-Y-|||--1 dfrac (1)(8) .dfrac (1)(8) dfrac (1)(8)-|||-0 .dfrac (1)(8) 0 dfrac (1)(8)-|||-1 .dfrac (1)(8) .dfrac (1)(8) .dfrac (1)(8)-|||-验证X和Y是不相关的,但X和Y不是相互独立的.

设随机变量X和Y的联合分布律为X -1-|||-Y 0 1-|||--1 dfrac (1)(8) dfrac (1)(8) dfrac (1)(8)-|||-

25.设随机变量（X,Y）的分布律为X-|||-Y -1 0 1-|||--1 dfrac (1)(8) dfrac (1)(8) dfrac (1)(8)-|

(13)设随机变量(X,Y)的联合概率分布如下.-|||-X-|||-①-|||-0 dfrac (1)(8) a dfrac (1)(4)-|||-1 dfr

设随机变量X的分布律为X -1 0 1-|||-P dfrac (1)(5) dfrac (3)(5) dfrac (1)(5)设X -1 0 1-|||-P

1.设随机变量X与Y的联合分布律为-|||-Y-|||-X -1 0 2-|||--1 dfrac (1)(6) dfrac (1)(12) 0-|||-0 d

1.设随机变量X与Y的联合分布律为-|||-Y-|||-X-|||--1 0 2-|||--1 dfrac (1)(6) dfrac (1)(12) 0-|||

设随机变量X,Y满足P(XY=0) =1,并且分布律分别为X -1 0 2 Y 0 1-|||-P dfrac (1)(6) dfrac (1)(3) dfra

设二维随机变量(X,Y)的分布律为-|||-Y 0 1 2-|||-0 dfrac (1)(4) 0 dfrac (1)(4)-|||-1 0 dfrac (1

[例2]设随机变量X与Y相互独立,其概率分布为-|||-x 0 1-|||-P .dfrac (1)(3) .dfrac (2)(3)-|||-Y 0 1-||

已知随机变量X的分布律为-|||-x 2 3 4 9-|||-p dfrac (1)(8) dfrac (5)(8) dfrac (1)(8) dfrac (1