For the year 2023, CVS Health Corporation reported total revenue of $350 billion, cost of goods sold of $220 billion, operating expenses of $100 billion, interest expense of $8 billion, and tax expense of $12 billion. The company’s total assets were $400 billion, and total liabilities were $180 billion.

1. Calculate the gross profit margin.
2. Determine the net profit margin.
3. Compute the debt-to-equity ratio.
4. Determine the return on equity (ROE).