Question

• 71. Evergreen Air Center is the world's largest parking lot for unwanted commercial aircraft. Airlines pay from $750 to $5,000 monthly for the storage services provided by Evergreen. Prior to September 2001, the company had 140 discarded airplanes at its Arizona facilities and was growing at a rate of about six planes monthly with about two a month sold for parts and/or scrap metal. After calamity struck the airline industry in September 2001, the airlines have retired over a thousand planes—many of which found their way to Evergreen. Now the actual number of planes stored at Evergreen differs significantly from the prediction based on previous behavior. This difference is referred to as

Answer 1

The actual number of planes stored at Evergreen Air Center post-September 2001 versus the predicted number based on prior trends is referred to as the residual, which in statistics is the difference between observed and predicted values.

Step-by-step explanation:

The difference between the actual number of planes stored at Evergreen after September 2001 and the prediction based on previous behavior before that date is referred to as the residual. In the context of statistics, a residual is the difference between an observed value and the value predicted by a model. Given that Evergreen Air Center was adding about six planes a month and selling two, a linear growth model might predict the number of planes at a future time. However, the unexpected event in September 2001 caused a deviation that would result in the actual number of planes being higher than the prediction, hence producing a large residual.