Kruskal-Wallis, Friedman and Mood nonparametric tests applied to business decision making

Abstract

The post COVID-19 crisis scenario demands continuous improvement in the quality of the products and services offered, supported by administrative and statistical tools that optimize business decision-making. In this research, three non-parametric statistical tests -Kruskal-Wallis, Friedman and Mood's median- are applied to three case studies in order to test the hypotheses posed, respectively: whether the distributions of the populations of the units sold by a distribution company are equal for three types of inputs, whether the stress levels differ or not for three types of work modalities in an automobile commercialization company and whether the medians of production yields in an agricultural company are equal or not for four varieties of fruit.  The solution is sought using standard procedures for each of the nonparametric tests.