Tesla, Inc. recorded total revenues of $100 billion and a cost of goods sold of $60 billion for 2023. The operating expenses were $25 billion, while the interest expense was $2 billion, and tax expense was $5 billion. The total assets of the company were reported to be $150 billion and total liabilities were $70 billion.

1. Calculate the gross profit margin.
2. Determine the operating profit margin.
3. Compute the interest coverage ratio.
4. Determine the return on equity (ROE).