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Time Series for Apple, Inc

The required Apple Inc sales data in attached Excel document.

You will therefore be required to collect historical unadjusted (i.e. should not be adjusted for seasonality) data for eight years, that will be used for these time series.


You must perform a complete time series analysis, making use of the following guidelines:

Double check that your data is NOT seasonally adjusted and that you have 8 years (must be either quarterly or monthly) of data in total.

Seasonal Variation

Trend Analysis

Based on the time series (original data) graph, describe the time series (i.e. before de-seasonalizing).
On the same graph as (a) graph the de-seasonalized time series.
Write out the Trend line equation provided by your computer (or manual) output and explain the meaning of the components (b0, b1) as they apply to your dependent variable. (De-seasonalize your data before finding the Trend Line).

Cyclical-Irregular variation


Show all detailed calculations.
Plot the actual and predicted values against time on the same graph.

Copy of the data.
Calculation of seasonal indices.
Calculation of Trend Line
Graph of original data and the trend line
Graph of Seasonal indices
Graph of Predicted and actual values vs. time.


Solution Summary

Step by step method for time series analysis is discussed here