AT&T Inc. has released financial statements for its Communications segment for the fiscal year ending December 31, Year 4.

Income Statement for Year Ended December 31, Year 4

• Sales revenue: $1,700,000
• Cost of goods sold: $1,020,000
• Gross profit: $680,000
• Operating expenses: $340,000
• Depreciation expense: $140,000
• Operating income: $200,000
• Interest expense: $80,000
• Other income: $60,000
• Net income: $180,000

Balance Sheet as of December 31, Year 4 Assets

• Cash: $700,000
• Accounts receivable: $720,000
• Inventory: $580,000
• Property, plant, and equipment (net): $1,400,000
• Other assets: $400,000
• Total assets: $3,800,000

Liabilities

• Accounts payable: $500,000
• Short-term debt: $450,000
• Long-term debt: $1,200,000
• Stockholders' equity: $1,650,000
• Total liabilities and stockholders' equity: $3,800,000

Required:

1. Calculate the gross profit margin.
2. Determine the operating income percentage.
3. Compute the return on equity (ROE).
4. Find the quick ratio.
5. Calculate the total debt to equity ratio.