So I could write variance with VAR, or I could write it as the standard deviation squared. So let me write that. The standard deviation of D, of our difference, squared, which is the variance, is going to be equal to the variance of our variable M, plus the variance of our variable W. Now this might be a little bit counterintuitive. This might have made sense to you if this was plus right over here, but it doesn't matter if we are adding or subtracting, and these are truly independent variables, then regardless of whether we're adding or subtracting, you would add the variances. And so we can figure this out. This is going to be equal to, the standard deviation of variable M is eight. So eight squared is going to be 64.