Grafmkr is is a simple graph plotting program with no pretensions of mathematics! It does not do equations! Will allows up to three, different coloured, curves, each of up to 250 points, on the graph. Do not expect marvels of this program! Means and weighted means are calculated automatically. The weighted mean method used is to sum all the values, then delete the highest and lowest and sum again. The process is repeated until all the points are deleted from the series. This method gives reduces the weight of the extreme values. [ read more about Grafmkr >> ]