}
        return new MeanAndVariance(mean, sumOfSquaresOfDeltas / values.length);
      }
    },
    KNUTH {
      @Override
      MeanAndVariance variance(double[] values, MeanAlgorithm meanAlgorithm) {
        if (meanAlgorithm != MeanAlgorithm.KNUTH) {
          throw new SkipThisScenarioException();
        }
        double mean = values[0];
        double s = 0.0;