Required: a. Use the high-low method to estimate the fxed and variable portions of overhead costs based on machine-hours. (Round "Variable cost" answer to 2 declmal places.) Variable cost (per machine hour) Fixed cost b. Managers expect the plant to operate at a monthly average of 1,500 machine-hours next year. What are the estimated monthily overhead costs, assuming no inflation? (Round "Variable cost" answer to 2 decimal places.)