Example of Trend Analysis

A marketing analyst wants to assess trends in tennis racquet sales. The analyst collects sales data from the previous five years to predict the sales of the product for the next 3 months.

  1. Open the sample data, TennisRacquetSales.MTW.
  2. Choose Stat > Time Series > Trend Analysis.
  3. In Variable, enter Racquets.
  4. Under Model Type, select Quadratic.
  5. Select Generate forecasts. In Number of forecasts, enter 3.
  6. Click OK.

Interpret the results

The trend analysis plot shows a general upward trend. There is curvature and the model appears to fit the data well, which indicates a good fit. The analyst can be confident in the forecasts for the next 3 months.

Method

Model typeQuadratic Trend Model
DataRacquets
Length60
NMissing0

Fitted Trend Equation

Yt = 324.35 + 0.492×t + 0.04694×t^2

Accuracy Measures

MAPE2.474
MAD9.462
MSD135.701

Forecasts

PeriodForecast
61528.984
62535.249
63541.608