Answers

Here are the answers to the preceding questions:

1. The following are the two steps:
   1. Review the data chart and decide whether the past has an influence on the present.
   2. Confirm the influence using the Durbin-Watson test.
2. The Durbin-Watson test uses the regression errors' fluctuation to see whether the past has an influence over present data.
3. The distance from the medium moving average to the Y value. In this example, the Y value is the quarterly car sales.
4. The season and the regression trend value.
5. Here are two elements of time-series data:
   1. A season component
   2. A trend component