Comparsion of the decisive operational and economical indicators in chosen group of tractors of the upper power class.

This work is focused on comparsion of the decisive operational and economical indicators in chosen group of tractors of the upper power class. Progress of the repair and maintainance costs in dependence on the year operational time is watched here. As a source data for analysis of the operational and maintainance cosi were used informations from actuarial documents. This data were processed by statistical methods called dispersion, standart deviation, correlation and regression