Excel's Formula - sisman

Chapter 17: Charting Techniques 461
Pressing F9 recalculates the worksheet, which generates new random increment values for E1:E3
and creates a new display in the chart. The variety (and beauty) of charts generated using these
formulas may amaze you.
Working with Trendlines
With some charts, you may want to plot a trendline that describes the data. A trendline points
out general trends in your data. In some cases, you can forecast future data with trendlines. A
single series can have more than one trendline.
To add a trendline, select the chart series and then choose Chart Tools➜Layout➜Analysis➜Trend
line. This drop-down control displays options for four types of trendlines. For additional options
(and more control over the trendline), select More Trendline Options, which displays the
Trendline Options tab of the Format Trendline dialog box (see Figure 17-22).
Figure 17-22: The Format Trendline dialog box offers several types of automatic trendlines.
The type of trendline that you choose depends on your data. Linear trends are the most common
type, but you can describe some data more effectively with another type.
The Trendline Options tab enables you to specify a name to appear in the legend and the number
of periods that you want to forecast (if any). Additional options enable you to set the intercept
value, specify that the equation used for the trendline should appear on the chart, and choose
whether the R-squared value appears on the chart.