I apologize in advance for a more statistical question. I am trying to find out whether a transformation of two random variables X and Y ( z= g(X,Y) ) exists whose expected value is E(X)/E(Y). obviously, it ain't E(X/Y). is there a book or place where I could learn this? (Also, I would be interested to learn more about the properties of E(X/Y) if they have been worked out (and not just when X and Y are independent), so if there is a book for this one, I would again be quite interested, too.) this is not an R topic, so please email me directly if you know where I could look. thanks in advance. again, apologies for the clutter... /iaw