MikaEnterprises has the following information available regarding costs at various levels of monthly production:

Production volume 7,000 10,000

Direct materials $ 70,000 $100,000

Direct labor 56,000 80,000

Indirect materials21,000 30,000

Supervisors' salaries 12,000 12,000

Depreciation on plant and equipment 10,000 10,000

Maintenance 32,000 44,000

Utilities 15,000 21,000

Insurance on plant and equipment 1,600 1,600

Property taxes on plant and equipment 2,000 2,000

Total $219,600 $300,600

Required:

a. Identify each cost as being variable, fixed, or mixed Be sure to label each answer clearly.