1. Granite Industries manufacturers various-sized plastic bottles for its Bear Oil line. The manufacturing cost for smaller bottles is $55 per unit, which includes fixed costs of $12 per unit. A proposal is offered to purchase small bottles from an outside vendor for $36 per unit plus $3 per unit for freight. Using differential analysis, determine the unit cost of buying the bottles and whether the company should make or buy these bottles, assuming that fixed costs are unaffected by the decision. Show your calculation.