Calculating and Using a Single Charging Rate 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): $1.35 per maintenance hour 1. Calculate a single charoing rate for the Maintenance Department, flound your answer to the nearest cent. per maintenance hour 2. Use the two rates to assign the costs of the Maintenance Department to the user departrients bosed on actual usage, calculate the toai anguit charged for maintenance for the year, x