Microsoft Excel 2013: Data Analysis and Business Modeling

Chapter 64. Ratio-to-moving-average forecast method

Questions answered in this chapter:

• What is the trend of a time series?

• How can I define seasonal indexes for a time series?

• Is there an easy way to incorporate trend and seasonality into forecasting future product sales?

Often, you need a simple, accurate method to predict future quarterly revenues of a corporation or future monthly sales of a product. The ratio-to-moving-average method provides an accurate, easy-to-use forecasting method for these situations.

In the Ratioma.xlsx file, you are given data for sales of a product during 20 quarters (shown later in Figure 64-1 in rows 5 through 24), and you want to predict sales during the next four quarters (quarters 21–24). This time series has both ...