X,Y (0,-1) (0,0) (0,1) (1,-1) (1,0) (1,1)
P 1/9 1/9 1/9 2/9 2/9 2/9
Z=XY -1 0 1 2
P =P(0,-1) =P(0,0)+P(-1,1) =P(0,1)+P(1,0) =P(1,1)
=1/9 =3/9=1/3 =3/9=1/3 =2/9
X,Y (0,-1) (0,0) (0,1) (1,-1) (1,0) (1,1)
P 1/9 1/9 1/9 2/9 2/9 2/9
Z=XY -1 0 1 2
P =P(0,-1) =P(0,0)+P(-1,1) =P(0,1)+P(1,0) =P(1,1)
=1/9 =3/9=1/3 =3/9=1/3 =2/9