Sxx - Variance Formula
where (s_x^2) is the sample variance of (x).
[ \widehat\mathrmVar(S_xx) = \frac2 S_xx^2n-1 ] sxx variance formula
Variance of a chi-squared random variable with (k) df is (2k): where (s_x^2) is the sample variance of (x)
[ S_xx = \sum_i=1^n (x_i - \barx)^2 ]
It seems you’re looking for a paper or derivation related to the term — a common notation in statistics, particularly in simple linear regression and sum of squares decomposition . sxx variance formula