Example 3 The joint probability mass function of
(x,Y)is given by
p(x,y)
=k(2x+3y),x=0,1,2;y=1,2,3. Find all the marginal and conditional probability distributions. Also find the probability distribution of
(x+Y). What is the expected value of (i)
x(ii)
x|Y||
=3. Find also the variance of
xand conditional variance of
x|Y||
=3.
