Let X and Y be positively correlated random variables Determ

Let X and Y be positively correlated random variables. Determine whether the following is true or false and explain why: -X and -Y are positively correlated -X and Y are positively correlated the covariance of -X and -Y is positive the slope coefficient obtained by regressing Y on X would be positive the slope coefficient obtained by regressing X on Y would be positive

Solution

a.

False. Because, with decrease in X, Y might not decrese.