Variables are independent if and only if (iff) their JOINT probability is equal to the product of their unconditional (aka, marginal) probabilities; i.e., if and only if Prob(X,Y) = Prob(X)*Prob(Y). Further, if variables are independent then their covariance (and correlation) is equal to zero, but the converse is not true.
Here is David's XLS: http://trtl.bz/2kucVOv
Here is David's XLS: http://trtl.bz/2kucVOv
