Financial Statement is the use of different calculations and formulas to determine the financial health of an organization. Lean Manufacturing and Activity Analysis is about eliminating waste and focusing on the movement of goods and services in respect to customer demand. In regards to financial statements, please pick out four ratios discussed in the chapter that would best analyze AT&T's.

Using these 4 Ratios:

1. Liquidity Ratio - Current Ratio

2. Profitability Ratio - Return to Total Assets

3. Solvency Ratio - Ratio of Liabilities to Stockholders' Equity

4. Efficiency - Accounts Receivable Turnover

Discuss why these are the best calculations for AT&T and in detail explain how they effectively analyze the financial health of that firm.

Please provide references with online link. Thank you.