All of that over, since we're talking about sample standard deviation, we have four data points, so one less than four is all of that over three. Now this actually simplifies quite nicely because this is zero, this is zero, this is one, this is one, and so you essentially get the square root of 2 3rds, which is, if you approximate, 0.816. So that's that, and the same thing is true for y. The sample mean for y, if you just add up one plus two plus three plus six over four, four data points, this is 12 over four, which is indeed equal to three, and then the sample standard deviation for y, you would calculate the exact same way we did it for x, and you get 2.160. Now with all of that out of the way, let's think about how we calculate the correlation coefficient. Now right over here is a representation for the formula for the correlation coefficient, and at first it might seem a little intimidating. Until you realize a few things.