Given any cubic or quartic equation with real coefficients, it can be transformed by a change of variable into a standard form, and thus solved by means of a double-sided scale (Fig. 1) in the case of ...

A Monte Carlo study (Wahl 1971) is compared to the study of Marks and Dunn (1974) which investigated the ability of three discriminant functions, the quadratic, best linear, and Fisher's linear ...