'------------------------------------------------------------------ 
 '   BCX Implementation of the Standard Deviation Function 
 '------------------------------------------------------------------ 
 SET A[] AS DOUBLE
   1, 5, 9, 3, 10, 4 ' Small Set Of Sample Data 
 END SET
 
 DIM Result AS DOUBLE ' The answer = 3.502380149323707 
 
 Result = StDev(&A[0], 6) : PRINT "The Standard Deviation = ", Result#
 
 FUNCTION StDev(Sample[] AS DOUBLE, Elements) AS DOUBLE
   DIM Total AS DOUBLE
   DIM Mean  AS DOUBLE
   DIM Srs   AS DOUBLE
   DIM Tmp   AS INTEGER
   FOR Tmp = 0 TO Elements - 1
     Total = Total + Sample[Tmp]
   NEXT
   Mean = Total / Elements
   FOR Tmp= 0 TO Elements - 1
     Srs = Srs + POW(ABS(Sample[Tmp] - Mean), 2)
   NEXT
   FUNCTION = SQRT(Srs / (Elements - 1))
 END FUNCTION

Result:

 The Standard Deviation =  3.50238014308365