question: public static double calculateTestStatistic ( MeanVariance mv1 , MeanVariance mv2 ) { final double delta = mv1 . getMean ( ) - mv2 . getMean ( ) ; final double relvar1 = mv1 . getSampleVariance ( ) / mv1 . getCount ( ) ; final double relvar2 = mv2 . getSampleVariance ( ) / mv2 . getCount ( ) ; return delta / Math . sqrt ( relvar1 + relvar2 ) ; }
target:  Calculate the statistic of Welch's t test using statistical moments of the provided data samples