1. The essence of incremental costing is measuring the cost incurred whether a product is sold or not. After all, it is not sold. Managers frequently make four common errors when developing valid estimates of actual costs. List and explain each of these errors providing an example 2. Which airports do Southwest Airlines choose to fly into? If you want to fly to Boston, you cannot -- you must fly to either Providence, RI, or Manchester, NH. To fly to New York City, you must fly to Islip, Long Island -. some distance from the City. Why fly into these smaller airports? Because they are much less congested than major airports like Boston's Logan Airport, New York's LaGuardia, or Kennedy Airports. Southwest's business model is based on low cost and low price, meaning they must fill their planes to capacity. 3. What is the relevance of the Total Contribution for comparison with pricing analyses? Furthermore, what is the new Total Contribution behavior regarding the baseline Total Contribution after a price change