Return-fit centered-sum and residual worksheet

Inspect the original static example

The CSV retains benchmark and asset returns, centered deviations, fitted values and residuals for the five-period record. Summary rows provide centered sums and residual squared sum in percentage-point units. It is not an automatically recalculating worksheet.

Reconcile the fitting line

Cross-product 21 divided by benchmark squared sum 10 gives slope 2.1. Asset mean 1.2% minus slope times benchmark mean zero gives intercept 1.2%.

Review the residual identities

Retain units and full calculation precision

Changing observations requires new means, centered sums, coefficients and residuals. Printed rounding can produce small reconciliation differences; retain unrounded values for the calculation. The identities validate this fitting calculation, not a causal or distributional assumption.