3. The expected costs for the Maintenance Department of Stazler, Inc., for the coming year include: Fixed costs (salaries, tools): $64,900 per year Variable costs (supplies): Estimated usage by: Assembly Department $1.35 per maintenance hour 4,500 Fabricating Department 6,700 Packaging Department 10,800 Total maintenance hours 22,000 Actual usage by: Assembly Department 3,960 Fabricating Department 6,800 10,000 20,760 Packaging Department Total maintenance hours i. Calculate a single charging rate for the Maintenance Department. ii. Use this rate to assign the costs of the Maintenance Department to the user departments based on actual usage. Calculate the total amount charged for maintenance for the year