The following costs relate to a manufacturing organization:

Item	Product/ Period	Variable/Fixed
Product components	Product	Fixed
Direct manufacturing labor	Product	Fixed
Supplies used in manufacturing	Product	Fixed
Production supervisor
Factory rent
Plant manager salary
Sales commissions
Distribution costs
Sales manager salary
Corporate office expenses

Classify each of these costs as being a product cost or a period cost. Also classify the costs as variable or fixed with respect to the volume of production. What inferences do you draw about the correspondence between the two concepts?