The cost data for BC Billing Solutions for the year 2020 is as follows:

Month January February March April May June July August September October November December Invoices Processed 12,000 8,000 1 ,ooo 7,000 5,000 10,000 1 1 ,ooo 9,000 5,000 9,000 8,000 1 1 ,ooo Overtime Wages $7,760 6,800 6,000 6,100 6,200 7,300 7,400 6,900 6,500 6,600 6,800 7,450