when is $xy expressed in terms of xbar what type of relationship can be drawn between mean and sum which pair represents xy? how much are xy and ybar does sum xy and yy what is mean of ybar? when you are expressing sum as xy what is sum(xy) in ybar sum(xy) as the mean is there any relation between $x$ and $y$ what is the relationship between sum and mean is sum(xy) in terms of xbar and ybar? how does sum (x,y) work when you use the sum xy in math what is the relation between xy and sum if xy is sum of xy, what is the relation? what is the relation between xy and sum if you find sum(x) in terms of xbar and ybar is there any relation between $sum(x,y)$ that can be expressed in terms of mean of these two series? what is a relationship between $sum and $xy in math terms what is sum of xy