Smart Stream Inc. uses the variable cost method of applying the cost-plus approach to product pricing. The costs of producing and selling 10,000 cell phones are as follows: Variable costs per unit: Smart Stream desires a profit equal to a 30% return on invested assets of $1,200,000. a. Determine the variable costs and the variable cost amount per unit for the production and sale of 10,000 cell phones. b. Determine the variable cost markup percentage for cell phones. Round to two decimal places. %