For a recent year, McDonald's company-owned restaurants had the following sales and expenses (in millions): Assume that the variable costs consist of food and packaging. payroll, and 40% of the general, selling, and administrative expenses. a. What is MeDonald's contribution margin? Round to the nearest tenth of a million cone decimal place). b. What is McDonald's contribution margin ratio? Round to one decimal place. c. How much would income from operations increase if same-store sales increased by $900 million for the coming year, with no change in the contribution margin ratio or