Keel Company's fixed overhead costs for the year are expected to be as follows: depreciation, $80,000; supervisory salaries, $92,000; property taxes and insurance, $26,000; and other fixed overhead, $14,500. Total fixed overhead is thus expected to be $212,500. Variable cost per unit are expected to be as follows: direct materials $17; direct labor, $9; operating supplies, $3; indirect labor, $4; and other variable overhead costs, $2.50. Prepare a flexible budget for the following levels of production: 15,000 units, 20,000 units, and 25,000 units. What is the flexible budget formula for the year ended December 31?