profitability ratios,

Identify four profitability ratios, and write out their equations.
Why is the basic earning power ratio useful?
Why does the use of debt lower the ROA?
What does ROE measure? Since interest expense lowers profits and
thus the ROA, does using debt necessarily lower the ROE? Explain.
A company has $20 billion of sales and $1 billion of net income. Its
total assets are $10 billion, financed half by debt and half by com-
mon equity. What is its profit margin? (5%) What is its ROA? (10%)
What is its ROE? (20%) Would ROA increase if the firm used less
leverage? (yes) Would ROE increase?