Consider a retail firm with a net profit margin of 3.94%, a total asset turnover of 1.86, total assets of $43.5 million, and a book value of equity of $17.8 million. a. What is the firm's current ROE? b. If the firm increased its net profit margin to 4.46%, what would be its ROE? c. If, in addition, the firm increased its revenues by 16% (maintaining this higher profit margin and without changing its assets or liabilities), what would be its ROE