In: Statistics and Probability
The joint probability distribution of variables X and
Y is shown in the table below.
...............................................................................X..........................................................................
The joint probability distribution of variables X and
Y is shown in the table below.
...............................................................................X.......................................................................
Y
|
1
|
2
|
3
|
1
|
0.30
|
0.18
|
0.12
|
2
|
0.15
|
0.09
|
0.06
|
3
|
0.05
|
0.03
|
0.02
|
- Calculate E(XY)
- Determine the marginal probability distributions of X
and Y.
- Calculate E(X) and E(Y)
- Calculate V(X) and V(Y)
- Are X and Y independent? Explain.
- Find P(Y = 2| X = 1)
- Calculate COV(X,Y). Did you expect
this answer? Why?
- Find the probability distribution of the random variable
X + Y.
i. Calculate E(X + Y)
directly by using the probability distribution of X + Y.
- Calculate V(X + Y) directly by using the probability
distribution of X + Y, and verify that V(X + Y) = V(X) + V(Y). Did
you expect this result? Why?