Calculates the sample mean for the grouped data which has been set using SetMidpoints or SetFrequencies.
Note that the mean of the grouped data is actually an approximation of the mean of the underlying data set. The reason for this is that here the midpoint of each grouped set of data is assumed to be the mean of that collection of data elements. However, in reality this will generally not to precisely the case,however it will generally be true that the midpoints are approximately equal to the mean and hence the sample mean using these values will be approximately equal to the mean of the data set.
GroupedData Class | WebCab.COM.Statistics.Statistics Namespace