$$S_xx = \sum (x_i - \barx)^2$$

s2=∑(xi−x̄)2n−1s squared equals the fraction with numerator sum of open paren x sub i minus x bar close paren squared and denominator n minus 1 end-fraction

, acting as a crucial measure of total variation for calculating variance and regression coefficients. The formula, defined either by squared deviations from the mean or a computational shortcut (

Now, calculate the squared deviations:

s squared equals the fraction with numerator sum of x sub i squared minus the fraction with numerator open paren sum of x sub i close paren squared and denominator n end-fraction and denominator n minus 1 end-fraction Relationship to Standard Deviation Variance is expressed in squared units