77 7 P1=P{Y=y1} 153010 P2=P{Y=y2}=P2 7113 301510 把这些数据补充到前面表上 0 pi 7/15 7/30 7/10 0 7/30 1/15 3/10 7/10 3/10 p
10 3 15 1 30 7 { } 10 7 30 7 15 7 { } 2 1 2 2 2 2 1 1 1 1 = = = = + = = = = = + = = = i i i i p P Y y p p P Y y p Y X 0 1 pi. 0 7/15 7/30 7/10 1 7/30 1/15 3/10 p.j 7/10 3/10 1 把这些数据补充到前面表上:
例2(旧书P63,新书P60) 求:例3.2.2中(X,Y)的分量X和Y的边缘分布 解:P(x=0)=P(x=,y=0}+(x=0,y=1 0.00013+0.19987=0.20000 P{X=1}=P{X=1,Y=0}+P{X=1,Y=1 0.00004+0.79996=0.80000 PY=0}=P{X=0,Y=0}+PX=1,Y=0} 0.00013+0.00004=0.00017 P{Y=1}=PX=0,y=1}+PX=1,Y=1} 0.19987+0.79996=0.99983 转下页
解: 例2 (旧书P63, 新书P60) 转下页 求:例3.2.2中(X,Y)的分量X和Y的边缘分布. P{X=0}= P{X=0,Y=0}+P{X=0,Y=1} = 0.00013+0.19987=0.20000 P{X=1}= P{X=1,Y=0}+P{X=1,Y=1} = 0.00004+0.79996=0.80000 P{Y=0}= P{X=0,Y=0}+P{X=1,Y=0} = 0.00013+0.00004=0.00017 P{Y=1}= P{X=0,Y=1}+P{X=1,Y=1} = 0.19987+0.79996=0.99983