A study was conducted to investigate the effect of a coal-fire generating plant upon the water quality of a river. As part of an environmental impact study, fish were captured, tagged, and released. The following information was recorded for each fish: sex(0=female, 1=male), length(cm), maturation (0=young, 1=adult), weight(g). The scales of these four variables (in order) are

>Nominal, ratio, ordinal, ratio