code: @JmxAttribute(optional = true)
  	public double getSmoothedStandardDeviation() {
  		if (totalCount == 0) {
  			return 0.0;
  		}
  
  		double avg = smoothedSum / smoothedCount;
  		double variance = smoothedSqr / smoothedCount - avg * avg;
  		if (variance < 0.0)
  			variance = 0.0;
  		return sqrt(variance);
  	}
docs: Returns smoothed standard deviation
  
  @return smoothed standard deviation