In statistics, specifically in the context of , $S_xx$ represents the Sum of Squares of the Deviations of X .
$$S_xx = \sum x^2 - \frac(\sum x)^2n$$
This formula is algebraically equivalent but is often preferred for hand calculations because it avoids calculating the mean first and dealing with messy decimals until the end. sxx variance formula
[ \widehat\mathrmVar(S_xx) = \frac2 S_xx^2n-1 ] In statistics, specifically in the context of ,