A general graphical method for evaluating experimental results that should fit a linear equation

Abstract

When the results of an experiment should be representable by a linear equation of the general form y= mx+ c the errors inevitably associated with the values of x_j and y_j(j= 1 to n >2) give rise to a set of n simultaneous equations that will be inconsistent. As an alternative to a least-squares computation, a graphical procedure is described for finding the best values of the constants m and c. The method is quite general and it is illustrated by worked examples of problems encountered in analytical chemistry, e.g., the potentiometric titration of a dibasic acid, the spectrophotometric determination of the stability of a weak complex, the evaluation of redox potentials and the liquid-liquid extraction of a weak monobasic acid.