Add, change, or remove a trendline in a chart
Applies to: Microsoft Office Excel 2007, Outlook 2007, PowerPoint 2007, Word 2007
You can add a trendline (trendline: A graphic representation of trends in data series, such as a line sloping upward to represent increased sales over a period of months. Trendlines are used for the study of problems of prediction, also called regression analysis.) or moving average (moving average: A sequence of averages computed from parts of a data series. In a chart, a moving average smooths the fluctuations in data, thus showing the pattern or trend more clearly.) to any data series (data series: Related data points that are plotted in a chart. Each data series in a chart has a unique color or pattern and is represented in the chart legend. You can plot one or more data series in a chart. Pie charts have only one data series.) in an unstacked, 2-D, area, bar, column, line, stock, xy (scatter), or bubble chart. A trendline is always associated with a data series, but a trendline does not represent the data of that data series. Instead, a trendline is used to depict trends in your existing data or forecasts of future data.
Note You cannot add a trendline to data series in a stacked, 3-D, radar, pie, surface, or doughnut chart.
Just traded in my old subtlety...
for a NUANCE!