why do you think x and y are positively correlated what is the proof that a variable is positively correlated with an integer how to prove value of y in data? how do you prove that e[x-y] is the smallest variable? when x is a standardized variable and is perfectly positively correlated with respect to each other, how to prove that x-y is 0 if x and y are standardized variables and are perfectly positively correlated with respect to each other, how can i prove that $e[(x-y)2] = 0$? if x and y are standardized variables what are the statistics of e if an x-y statistic is positive and negative, how can i prove how do you prove the value of e of a standardized variable what is the proof that all the variables are positively correlated? what is the proof that x and y are standardized variables and are perfectly positively correlated with respect to each other? is y a standardized variable which standardized variable is positively correlated if x and y are standardized variables and are perfectly positively correlated with respect to each other, how can i prove that $E[(x-y)2] = 0$ if x and y are standardized variables and are perfectly positively correlated with respect to each other, how can i prove that $e[(x-y)2] = 0$ if y and x are standardized variables and are perfectly positive correlated with respect to each other what's the proof of zero for a statistic? if you use statistics how do you prove that a variable is zero when x and y are standardized variables and are perfectly correlated with respect to each other, how can i prove that x-y is 0$?