5. Fixed costs can be discretionary or committed. Using your judgment based on the discussion in the case, identify which costs are likely to be discretionary. Assuming that management is able to decrease discretionary fixed costs by 10%, what would be the impact on Bridgestone's break-even point revenues? 6. As Bridgestone operates during the next year, do some services deserve more attention than others? (Hint: What is their relative contribution to the WACM % and to the total contribution margin? Which services?) 7. How can the budgetary weighted average contribution margin (WACM) percentage be used to help control the actual operations of Bridgestone?