$($a$)$ Identify which of the following transactions and events are product costs and which are period

costs:

$$ Office fire insurance.

$$ Cost of electric power.

$$ Rental charges of warehouses.

$$ Costs of basic raw materials used in production.

$$ Depreciation of electrical equipment in the plant.

$$ Depreciation of the furniture in the office.

$$ Sales incentives paid to the sales personnel.

$$ Inspection costs of raw materials.

$$ Direct overhead costs.

$$ Costs of packing materials.

$($b$)$ Identify which of the following costs are fixed, which are variable, and which are mixed.

$$ Maintenance costs of vehicles used in supplying

goods.

$$ Direct labor cost.

$$ Wages paid to machine operators.

$$ Depreciation of factory buildings.

$$ Salaries paid to quality control inspectors.

$$ Advertising expenses.

$$ Costs of direct materials.

$$ Employee fidelity insurance.

$$ Cost of electric power.

$$ Sales taxes.