The maintenance department of the ABC Corp. provides services to the other departments of the company. The table below shows the costs of this department at standard workload (3,000 working hours) and at excessive workload in the month of May (4,200 working hours). Salary of engineers and parts used in repairs vary with the output, the other costs don't vary. Calculate the amount of the maintenance department costs that should be allocated to the sales department, if in ordinary months the sales department consumes 1, 200 working hours of the maintenance department; however in December the maintenance department worked 2,940 hours for the sales department