In early 2018, United Airlines (UAL) had a market capitalization of $20.5 billion, debt of $14.1 billion, and cash of $3.7 billion. United Airlines had revenues of $37.8 billion. Southwest Airlines (LUV) had a market capitalization of $35.7 billion, debt of $3.1 billion, cash of $2.66 billion, and revenues of $18.23 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