In previous videos, we took this bivariate data and we calculated the correlation coefficient. And just as a bit of a review, we have the formula here. And it looks a bit intimidating, but in that video we saw all it is is an average of the product of the z-scores for each of those pairs. And as we said, if r is equal to one, you have a perfect positive correlation. If r is equal to negative one, you have a perfect negative correlation. And if r is equal to zero, you don't have a correlation. But for this particular bivariate data set, we got an r of 0.946, which means we have a fairly strong positive correlation.