Moe's Machines has the following costs in a period when production is 2,000 units: Direct materials, $8,500; direct labor (variable), $9,000; straight-line depreciation, $800; rent (same every month), $1,200; and other fixed costs, $1,000. If production changes to 1,800 units, the total variable costs and total fixed costs will be

$15,750 and $3,000.

Please show how to cal $3,000 as a fixed costs and why?