Peggy -

I have graphed some data where each data point is the average of 5
replicates. I did the statistics in a program other than Excel. In my
Excel graph, under 'Format Data Series' I have never understood how to add
y error bars. It seems to me the data set that generated the graph doesn't
have enough information to do this. It doesn't know the value of each of
the five replicates, just the average. What am I missing? <

A measure of variation?

Like range or standard deviation.

- Mike

www.mikemiddleton.com