Calculating mean and standard deviation in gnuplot

[Rishabh Gupta]

Hi all,
Could somebody tell whether there is a way of calculating the mean and
standard deviation of a given data set within gnuplot. For example could I
use the fit function to fit the data set to an equation that represents the
mean and standard deviation.
In addition does any one know what would be best technique of plotting
the mean and standard deviation on top of the original data set. Ideally I
would like a box to represent the mean at its center and the standard
deviation at the border.

Any help would be greatly appreciated.

Many Thanks

Rishabh