Q10. (LSS 5.8) Given the following probability distribution for variables X and Y.
P(Xi,Yi) 0.2 0.4 0.3 0.1
X -100 50 200 300
Y 50 30 20 20
Compute a. E(X) and E(Y ). b. σX and σY . c. σXY . d. E(X+Y). e. By looking at the joint distribution, do you expect the correlation coefficient to be positive or negative? Why? f. Verify your answer for e) by computing the correlation coefficient.
