Vinyl Resting Place Company manufactures vinyl records only. Annual production costs incurred in the manufacturing process are shown below for two levels of production. Costs Incurred Production in Units 7,500 15,000 Total Cost/ Total Cost/ Production Costs Cost Unit Cost Unit Direct materials $12,000 $1.60 $24,000 $1.60 Direct labor 14,250 1.90 28,500 1.90 Utilities 3,000 0.40 4,500 0.30 Rent 6,000 0.80 6,000 0.40 Maintenance 1,200 0.16 1,750 0.12 Supervisory salaries 1,500 0.20 1,500 0.10 Instructions (a)Define the terms variable costs, fixed costs, and mixed costs. (b)Classify each cost above as either variable, fixed, or mixed.