SET A# []  = 320, 380, 400, 420, 500, 520, 600, 660, 720, 780

DIM  SD  AS DOUBLE
DIM  MN  AS DOUBLE
DIM  CI  AS DOUBLE

MN = Average( &A[0],10) : MN=ROUND(MN,2) : PRINT "Average = ", MN#
SD =  StDev ( &A[0],10) : SD=ROUND(SD,2) : PRINT "Standard Deviation  = ", SD#
CI =   Ci   ( 5280,2)   : CI=ROUND(CI,2) : PRINT "Confidence Interval = ", CI#



FUNCTION Ci OPTIONAL ( Average#, Count#, Z# = 1.96 ) AS DOUBLE
'------------------------
' Z = 68% = 1
' Z = 95% = 1.96
' Z = 99% = 2.58
'------------------------
LOCAL T1  AS DOUBLE
LOCAL T2  AS DOUBLE
LOCAL L1  AS DOUBLE
'------------------------
L1 = 100 / SQRT(Count)
T1 = MN - (Z#*L1)
T2 = MN + (Z#*L1)
FUNCTION = T2-T1
END FUNCTION




FUNCTION StDev ( Sample [] AS DOUBLE , Elements ) AS DOUBLE
'------------------------
LOCAL Total AS DOUBLE
LOCAL Srs   AS DOUBLE
LOCAL Tmp   AS LONG
LOCAL Average  AS DOUBLE
'------------------------
FOR Tmp = 0 TO Elements-1
  Total = Total + Sample [Tmp]
NEXT
Average = Total / Elements
FOR Tmp= 0 TO Elements-1
  Srs = Srs + POW(ABS(Sample [Tmp]-Average ),2)
NEXT
FUNCTION = SQRT (Srs/(Elements-1))
END FUNCTION




FUNCTION Average ( Sample [] AS DOUBLE, Elements ) AS DOUBLE
'------------------------
LOCAL Total AS DOUBLE
LOCAL Tmp
'------------------------
FOR Tmp = 0 To Elements - 1
  Total = Total + Sample [Tmp]
NEXT
FUNCTION = Total / Elements
END FUNCTION