Truman Inc. has provided the following production and total cost data for two levels of monthly production volume - production volume 7,000 units 10,000 units - direct materials $70,000 $100,000 - direct labor $56,000 $80,000 - depreciation on factory equipment $10,000 $10,000 - depreciation on office equipment $5,000 $5,000 - utilities for factory $11,600 $12,500

the best estimate of the total monthly fixed manufacturing cost is