Stony Electronics Corporation manufactures a portable radio designed for mounting on the wall of the bathroom. The following list represents some of the different types of costs incurred in the manufacture of these radios: 1. The plant manager's salary. 2. The cost of heating the plant. 3. The cost of heating executive offices. 4. The cost of printed circuit boards used in the radios. 5. Salaries and commissions of company salespersons. 6. Depreciation on office equipment used in the executive offices. 7. Depreciation on production equipment used in the plant. 8. Wages of janitorial personnel who clean the plant. 9. The cost of insurance on the plant building. 10. The cost of electricity to light the plant. Required: Classify each of the items above as product (inventoriable) cost or period (noninventoriable) cost for the purpose of preparing external financial statements.