ABC Firm reports the following for the first three months of 2020: January February March Units Produced Units Sold 6,000 3,500 8,000 8,800 4,500 4,000 COGS Direct Materials Used Depreciation Shipping Cost Rent Utilities in Factory $37.700 19,500 7,500 4,900 3,125 16,500 $69,500 26,000 7,500 12,320 3,125 19,100 $40,700 14,625 7,500 5,600 3,125 14,550 1. For each cost, determine whether it is fixed, variable or mixed. You will have to think carefully about the appropriate level of activity for each cost: units sold or units produced. 2. Prepare a cost function for each cost