Consider a retailing firm with a net profit margin of 3.1%, a total asset turnover of 1.86, total assets of $44.6 million, and a book value of equity of $18.7 million. a. What is the firm's current ROE? b. If the firm increased its net profit margin to 3.6%, what would be its ROE? c. If, in addition, the firm increased its revenues by 24% (while maintaining this higher profit margin and without changing its assets or liabilities), what would be its ROE