Forecasting time series automatically in Excel

Now that we have forecast a time series the hard way, understanding every step, we can do it the easy way. We will use Excel's built-in functions to predict the future number of passengers. Perform the following steps:

1. Select both columns, TravelDate and Passengers, corresponding to the time and number of passengers.
2. Navigate to Data in the main menu.
3. Select Forecast Sheet (see the following screenshot for reference):

4. A window will pop up, showing a preview of the forecast and giving us the chance to change some parameters by clicking in Options:

• • Forecast End: We can choose the end of the forecast period. By default, Excel forecasts three seasons ahead (more on this to follow).
  • Forecast Start: We can do the same with the start of the forecast period. Default is the last point in time of our time series.
  • Confidence interval...