Originally Posted by

**continously confused** I'm just very confused about conditional density function. like the question is to show that Ey[E(X|Y)] = E(X)

x=0 x=1 x=2 x=3

y = 0 o.o4 o.o5 o.o6 o.o7

y=1 o.o6 o.o8 o.o7 o.o9

y=2 o.1 o.11 o.13 o.14

well i think that E(X) is

0x.04 + 0x.06 + 0x.1 + 1x.05 + 1x.08 + 1x.11 + 2x.06 + 2x.07 + 2x.13 + 3x.07 + 3x.09 + 3x.14 = 1.66

and that E(X|Y) = P(x,y)/P(y) this is p(x|y) not E(X|Y)

but the thing is that i dont know how to calculate P(x,y). Can someone explain it to me please?