YZ Corporation's financials include:

• Total assets: $900,000
• Total liabilities: $300,000
• Common stock: $250,000
• Preferred stock: $50,000
• Retained earnings: $200,000
• Net income: $100,000
• Total revenues: $600,000

Determine: a) Debt-to-total-assets ratio b) Price-to-book ratio c) Return on common equity d) Earnings per share