QuartilesOfNumCells
Declaration: 
TDataTable.QuartilesOfNumCells (LowCol, LowRow, HighCol, HighRow: integer; var Q1, Q2, Q3: double; var NumData: integer): boolean; 
The function QuartilesOfNumCells returns the quartiles of the distribution of all numeric elements (cells which are neither marked as csNAN, nor as csUndefined and which belong to either interval or ratio scaled variables) in the range of the matrix defined by the parameters LowCol, LowRow, HighCol, and HighRow. The first, second, and third quartile are returned in the variable parameters Q1, Q2, and Q3, respectively. The variable parameter NumData returns the number of data points used for the calculation (i.e. the number of numeric data cells within the specified range).
Please note that the second quartile Q2 is often denoted as the median of the distribution. The function returns a TRUE value if the quartiles are valid. A returned FALSE value indicates a memory overflow problem.

Hint: 
Setting both the low and high parameter of a dimension (i.e. LowCol and HighCol) to zero values forces the method to use all elements of that dimension. 
