The paper addresses the problem of the purposefulness of using statistical and mathematical methods in the analysis of production, costs and gross margins. The research shows that the application of variance analysis may increase the level of reliability of conclusions, it does not, however, question most conclusions based on the analysis of table lists. The selection of detailed tests should take account of the nature of the distribution of analyzed variables. Since most variables do not meet the conditions of normal distribution, nonparametric tests should be used in most cases.