Rem. ZDATis now a two variable statistics ta-
ble and not a simple statistics frequency table.
Frequency polygon KXDAT
Creates a cumrmilative frequency polygon from KXDAT.
Linear regression and correlation
A straight line is fitted by the use of least squares from the ta-
ble ID AT. The line will be given as Y = aX+b, where X is
the data in the second column in 2DAT.
The correlation coefficient is a measure of the goodness of
the fit and a value between -0.7 and 0.7 is a good fit.