f(x,y)=(x+y)/30 for x=0,1,2,3; y=0,1,2
here is the chart for the probability of f(x,y), i.e., P(0,0)=0, P(1,0)=1/30, P(1,1)=2/15 ...
0 1/30 1/10 1/5
1/30 2/15 3/10 8/15
1/10 3/10 3/5 1
But when I use the chart, the answer is 31/10. So I don't know why, can you tell me how will you gonna do to solve this problem? Thanks
The sums of the last row and column should both be 1 which should be the sum of all the elements in the table if this truly represents the joint distribution of (x,y), but they do not, they are .
So there is an error in your table.