Sierra Company produces its product at a total cost of $90 per unit. of this amount, $30 per unit is selling and administrative costs. The total variable cost is $72 per unit, and the desired profit is $10.80 per unit. Determine the markup percentage using the (a) total cost, (b) product cost, and (c) variable cost methods. Round your answers to one decimal place. a. Total cost 126 b. Product cost 36 X % c. Variable cost 15 X 96