The following variable production costs apply to goods made by Thornton Manufacturing Corporation: Item Cost per unit Materials $ 7.00 Labor Variab 8.50 rhead 0.75 Total $16.25 Required Determine the total variable production cost, assuming that Thornton makes 8,000, 18,000, or 28,000 units. Units Produced 8,000 18,000 28,000 Total variable cost