Three managers of the Magic Potion Company are discussing

Three managers of the Magic Potion Company are discussing a possible increase in production. Each suggests a way to make this decision.
HARRY: We should examine whether our company’s productivity—gallons of potion per worker—would rise or fall.
RON: We should examine whether our average cost—cost per worker—would rise or fall.
HERMIONE: We should examine whether the extra revenue from selling the additional potion would be greater or smaller than the extra costs.