I have the following data:

col 1 col 2 col3
_________________
4 12 18
5 15 31
6 13 19

I would like to create a barchart that shows ONLY ONE bar for the mean of
the columns. I know I could create the data separately with only the mean and
the bar chart will show up as I want it. BUT I would like to show a Y error
bar showing standard deviation for each of the columns.

Can this be done?

Thanks in advance.

Attila