Adding Trendlines

Problem

You've plotted your time series using Excel's charting feature and now you'd like to add a trendline.

Solution

Figure 6-2 shows an example linear trendline you can create on Excel charts. Notice that you also have the option of displaying the trendline equation on the chart, as shown in the figure.

Figure 6-2. Linear trendline

Excel also supports nonlinear trendlines . Figure 6-3 shows the same time series with a second-order polynomial trendline instead of a linear trendline.

Figure 6-3. Polynomial trendline

To create a trendline for a given data series, select the series by clicking on it and then right-click to reveal a pop-up menu. Select Add Trendline from the pop-up menu to open the Add Trendline dialog box, where you can select the type of trendline and other options. Refer to Chapter 8 to learn more about adding these and other types of trendlines to Excel charts.