Following is a list of various costs incurred in producing toy robotic helicopters. With respect to the production and sale of these toy helicopters, classify each cost as either variable, fixed, or mixed.
1. Property taxes, $ 210,000 per year on factory building and equipment
2. Janitorial costs, $ 5,000 per month
3. Metal
4. Packaging
5. Salary of plant manager
6. Oil used in manufacturing equipment
7. Cost of labor for hourly workers
8. Plastic
9. Straight- line depreciation on the production equipment
10. Computer chip (purchased from a vendor)
11. Electricity costs, $ 0.10 per kilowatt- hour
12. Rent on warehouse, $ 12,000 per month plus $ 20 per square foot of storage used
13. Pension cost, $ 0.75 per employee hour on the job
14. Hourly wages of machine operators
15. Property insurance premiums, $ 2,000 per month plus $ 0.008 for each dollar of property over $ 1,000,000