Consider a retail firm with a net profit margin of 3.58%, a total asset turnover of 1.87, total assets of $44.4 million, and a book value of equity of $17.9 million. a. What is the firm's current ROE? b. If the firm increased its net profit margin to 4.29%, what would be its ROE? c. If, in addition, the firm increased its revenues by 20% (maintaining this higher profit margin and without changing its assets or liabilities), what would be its ROE?