To use all data in calculating the trendline, you must have all the data
in one series. If they are in multiple series as an artifact of data
arrangement on you worksheet, then use a helper column to combine them.
If they are in multiple series to enable each series to have a
different format, then the first series should contain all the data (and
drive the trendline), then overlay with the individual series for
formatting purposes.

Jerry

Libby wrote:

I am almost finished a graph which contains 7 data series. I would like to a
a trend line that takes into consideration all the data series, therefore
showing the general trend of all the data.

I dont have the knowledge or experience with Excel to work out a solution.

Any help would be appreciated greatly.

Libby