In january 2016, united airlines (ual) had a market capitalization of $ 20.57 billion, debt of $ 12.04 billion, and cash of $ 5.35 billion. united airlines had revenues of $ 39.68 billion. southwest airlines (luv) had a market capitalization of $ 27.62 billion, debt of $ 3.04 billion, cash of $ 3.16 billion, and revenues of $ 19.61 billion. a. compare the market capitalization-to-revenue ratio (also called the price-to-sales ratio) for united airlines and southwest airlines. b. compare the enterprise value-to-revenue ratio for united airlines and southwest airlines. c. which of these comparisons is more meaningful? explain.