Consider the following joint distribution of X and Y. For example, P(X=-200, Y=-100) = .3, P(X=-200, Y=100) = .1, etc.
|
XY
|
-100
|
100
|
|
-200
|
0.3
|
0.1
|
|
200
|
0.2
|
0.4
|
a) Calculate the mean and variance of X
b) Calculate the mean and variance of Y.
c) Calculate the covariance and correlation between X and Y. Is there a positive or negative relationship between X and Y? Is the relationship strong, weak or moderate?