Average line in charts for Excel 97

[pi]

Hi
I have values in a worksheet which are shown on a chart in another worksheet. The values are sales figures for each month of the year to date.
If 5 months have been recorded then an average is obtained and I have inserted an average line onto the chart-manually.
Is it possible that the average line can be updated, dynamically, if the values have been changed or more columns have been added.

Thanx in advance
Dasi

 

[Chance1234]

have the average figure next to your table of data then simply plot this range on the graph

 

[pi]

Hi Chance1234

Please forgive my ignorance but how do you plot the average as a line

Thanx
Dasi