@Override public double conf(double totalWeight,double delta){
  return inverseNormal(1 - delta / 2) / (2 * Math.sqrt(totalWeight));
}

@ Override public double conf ( double totalWeight , double delta ) { return inverseNormal ( 1 - delta / 2 ) / ( 2 * Math . sqrt ( totalWeight ) ) ; }
calculate confidence intervall without a specific rule for instance averaging functions .
