Amazon.com, Inc. provided the following financial data for its North America segment for the fiscal year ended December 31, Year 4.

Income Statement for Year Ended December 31, Year 4

• Net sales: $300,000
• Cost of goods sold: $180,000
• Gross profit: $120,000
• Operating expenses: $60,000
• Advertising expenses: $20,000
• Depreciation expense: $15,000
• Operating income: $25,000
• Interest expense: $10,000
• Other income: $5,000
• Net income: $20,000

Balance Sheet as of December 31, Year 4 Assets

• Cash: $50,000
• Accounts receivable: $60,000
• Inventory: $70,000
• Property, plant, and equipment (net): $150,000
• Intangible assets: $20,000
• Total assets: $350,000

Liabilities

• Accounts payable: $30,000
• Short-term debt: $20,000
• Long-term debt: $50,000
• Stockholders' equity: $250,000
• Total liabilities and stockholders' equity: $350,000

Required:

1. Compute the gross profit margin.
2. Determine the operating income as a percentage of net sales.
3. Calculate the return on equity (ROE).
4. Find the quick ratio.
5. Compute the long-term debt to equity ratio.