VAR
      SUBROUTINE VAR(X,N,IWRITE,XVAR)
  
PURPOSE--This subroutine computes the sample variance (with
         denominator N-1) of the data in the input vector X.
         The sample VARIANCE = (The sum of the squared
         deviations about the sample mean/(N-1).
INPUT  ARGUMENTS--X      = The single precision vector of
                           (unsorted or sorted) observations.
                --N      = The integer number of observations
                           in the vector X.
                --IWRITE = An integer flag code which (if set to
                           0) will suppress the printing of the
                           sample variance as it is computed;
                           or (if set to some integer value not
                           equal to 0, like, say, 1) will cause
                           the printing of the sample variance
                           at the time it is computed.
OUTPUT ARGUMENTS--XVAR   = The single precision value of the
                           computed sample variance.
OUTPUT--The computed single precision value of the sample
        variance (with denominatorlue of the sample
PRINTING--None, unless IWRITE has been set to a non-zero integer,
          or unless an input argument error condition exists.
RESTRICTIONS--There is no restriction on the maximum value of N
              for this subroutine.
OTHER DATAPAC   SUBROUTINES NEEDED--None.
FORTRAN LIBRARY SUBROUTINES NEEDED--None.
MODE OF INTERNAL OPERATIONS--Single precision.
LANGUAGE--ANSI FORTRAN.
REFERENCES--Snedecor and Cochran Statistical Methods,
            Edition 6, 1967, Page 44.
          --Dixon and Massey, Introduction to Statistical
            Analysis, Edition 2, 1957, Page 38.
          --Mood and Grable 'Introduction to the Theory of
            Statistics, Edition 2, 1963, Page 171.
WRITTEN BY--James J. Filliben
            Statistical Engineering Laboratory (205.03)
            National Bureau of Standards
            Gaithersburg, MD  20899
            Phone--  301-921-2315
ORIGINAL VERSION--June      1972.
UPDATED         --September 1975.
UPDATED         --November  1975.