A sociological study was conducted to determine whether there was a significant difference in the earnings of four groups of employees working in financial institutions, according to their level of education, in the first year of their employment. For this purpose, data were used on the annual income (in thousand BGN) of four groups of employees, according to their level of education. Denmark is presented in the following table: Level of educati secondary education Professional Master's Bachelor Bachelor degree on Employees 1 11,5 12,5 14,5 17,5 2 10,5 15,2 13,2 16,9 3 12,6 13,6 12,3 18,8 4 15,4 15,4 15,7 22,7 5 14,7 16,1 17,8 19,9 6 11 12,4 13,6 23 Use a significance level of = 0.05 to test the claim that there is no difference in the annual earnings of the four groups of employees.