In an adjacent row/column compute the average of the data series. You should
as many data points as in your series.
Plot both series in a column chart. Select the average series, then
right-click and select 'Change chart type' Change the chart type to a Line
Chart. Since you had selected a series the change affects only that series.
Select the original data series (the column chart) and add error bars of
size 1 standard deviation. In Excel 2007 select the chart, then the
contextual tab Chart Tools | Layout. In there from the Analysis group select
the Error Bars drop down.
FWIW, the error bar range you specified corresponds to the standard
deviation of the population, not the sample. Maybe, that's what you want but
by default Excel will give you the std. dev. of a sample.
--
Tushar Mehta
http://www.tushar-mehta.com
Custom business solutions leveraging a multi-disciplinary approach
In Excel 2007 double-click to format may not work; right click and select
from the menu