One of the forecasting methods we will learn in the future deals with seasonality. Seasonality should only be used when the data has a repeatable pattern of repetition. The number of data points before the pattern repeats is called the period of the data. The data show below has a period of four:

The period is four because the pattern repeats every four data points. If the pattern did not repeat, then the data is random and seasonality would not be appropriate. There is no period if the pattern does not repeat.

Find the period for the following graphs:

The period of the graph above is:

The period of the graph above is:

The period of the graph above is:

The period of the graph above is:

Possible Answers: none, 2, 3, 4, 5, 6, 7, 8