Assigning shares of "relative importance" to each of a set of regressors is one of the key goals of researchers applying linear regression, particularly in sciences that work with observational data.

To calculate the sum of squares, subtract the mean from the data points, square the differences, and add them together. There are three types of sum of squares: total, residual, and regression.

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The residual sum of squares (RSS) is a statistical technique used to measure the variance in a data set that is not explained by the regression model.