3. McDonald's Corporation, a leading fast-food chain, presents the following financial figures for the fiscal year ending December 31, 20XX:
   • Total revenue: $25 billion
   • Cost of goods sold: $10 billion
   • Selling, general, and administrative expenses: $8 billion
   • Depreciation and amortization expense: $2 billion
   • Operating income: $5 billion
   • Interest expense: $1 billion
   • Income tax expense: $1.5 billion

Calculate the following financial ratios for McDonald's Corporation:

a) Earnings Before Interest and Taxes (EBIT) margin b) Net profit margin c) Return on assets (ROA) d) Return on equity (ROE)