public static double xbarVariance ( double variance , int sampleN , int populationN ) { if ( populationN <= 0 || sampleN <= 0 || sampleN > populationN ) { throw new IllegalArgumentException ( "All the parameters must be positive and sampleN smaller than populationN." ) ; } double xbarVariance = ( 1.0 - ( double ) sampleN / populationN ) * variance / sampleN ; return xbarVariance ; }
Calculates Variance for Xbar for a finite population size