Sxx (Sum of Squares about the Mean) — Variance Formula

Definition

Sxx (also written SSx or SS_total for a single variable) is the sum of squared deviations of observations x_i from their mean x̄:

Where ( s_e^2 ) is the variance of the residuals (mean squared error).

Sxx = Σ(xi - x̄)²

Sxx = Σ(xi - x̄)²

Example:

Suppose you have 5 exam scores: 70, 75, 80, 85, 90.

from the mean. Here is the breakdown of how to understand and calculate it. 1. The Formula

[ SE(b) = \sqrt\fracs_e^2S_xx ] where ( s_e^2 ) is the residual variance.

Analysis of the cap S sub x x end-sub Formula in Statistical Variance and Regression cap S sub x x end-sub represents the corrected sum of squares for a variable

Formula 1 (Definitional):

[ S_xx = \sum_i=1^n (x_i - \barx)^2 ]