Trendlinie Excel. Click the plus icon found on the upper right side of the chart. If you don t see the icon click the chart.
In the add trendline dialog box select any data series options you want and click ok. You can also extend trendlines to forecast future data. Choose a trend regression type.
Specify the number of periods to include in the forecast.
Add a trendline select a chart. Click the plus icon found on the upper right side of the chart. Type 3 in the forward box. Specify the number of periods to include in the forecast.