Purchases. All of these would be included in the denominator. Question 3 3 pts Under the dollar-value LIFO retail method, to determine the value of a LIFO layer: Divide the LIFO layer by the layer-year price index and multiply by the layer-year cost-to-retail percentage. Multiply the LIFO layer by the base year price index and the current year cost-to-retail percentage. Multiply the LIFO layer by the layer-year price index and by the layee-year cost-to-retail percentage. Divide the LIFO layer by the layer-year cost-to-retail percentage and multiply by the layer-year price index. Engineering follow-through on an early phase of commercial production Quality control during commercial production Routing ongoing efforts to refine, enrich, or otherwise improve on the qualities existing product None of these answers is an example of an R&D cost