Compare the financial performance of CVS and Southwest Airlines Co. on the basis of profitability in 2011 and 2010. Use the following ratios: profit margin, asset turnover, return on assets, and return on equity. In 2009, total assets, total stockholders' equity, and cash flows from operating activities for CVS were $61,141 million, $35,768 million, and $4,035 million, respectively. Southwest's total assets were $14,269 million in 2009, and its total stockholders' equity and cash flow from operating activities were $5,454 million and $985 million, respectively. Comment on the relative performance of the two companies. In general, how does Southwest's performance compare to CVS's with respect to profitability? What distinguishes Southwest's profitability performance from that of CVS?