And then once you figure out the variance, you just take the square root for the standard deviation. The variance of x is similarly going to be the sum of the variances of these n y's. So it's going to be similarly n times the variance, n times the variance of y. So this all boils down to what is the variance of y going to be equal to? So let me scroll over a little bit, get a little bit of more real estate, and I will figure that out right over, right over here. All right, so we want to figure out the variance of y. So variance of y is going to be equal to what?