Chirp Chirp Industries makes custom deluxe birdhouses. Below is a list of some of the products that are used to construct these birdhouses. Determine if these costs are fixed or variable costs.

$6,000 per year - depreciation for building equipment
Dependent on order - glue, paint, and other materials to build the houses
$25 per board foot - wood to make the birdhouses
$65,000 per year - salary for shop supervisor
$3,000 per month - Selling and Administrative Costs
$10,000 per month - rent for office building
$15 per hour - factory labor to build the houses