Sxx Variance Formula -

[ \fracS_xx\sigma_x^2 \sim \chi^2_(n-1) ]

[ \mathrmVar(S_xx) = 2(n-1)\sigma_x^4 ] We know: sxx variance formula

But if we treat (x_i) as (e.g., in observational studies, random sampling from a bivariate population), then (S_xx) is a statistic with a sampling distribution. in observational studies