--  CONFIDENCE.NORM returns the confidence interval
--  for a population mean, assuming a normal distribution
--  CONFIDENCE.T uses a Student's T distribution instead
--
--      CONFIDENCE.NORM ( Alpha, StandardDev, SampleSize )
--
--  Confidence level equals 100*(1-alpha)%
--  Alpha 0.05 indicates a 95% confidence level
DEFINE
    TABLE SampleData = { 2, 4, 4, 4, 5, 5, 7, 9 }
    VAR Mean         = AVERAGE ( SampleData[Value] )
    VAR StandardDev  = STDEV.S ( SampleData[Value] )
    VAR SampleSize   = COUNTROWS ( SampleData )
    VAR Alpha        = 0.05 -- 95% confidence level
EVALUATE
{
    ( "AVERAGE",          Mean ),
    ( "STDEV.S",          StandardDev ),
    ( "CONFIDENCE.NORM",  CONFIDENCE.NORM ( Alpha, StandardDev, SampleSize ) ),
    ( "CONFIDENCE.T",     CONFIDENCE.T    ( Alpha, StandardDev, SampleSize ) )
}