class LogNormalVolatilityEstimateConfidenceIntervalCalculator {

  public ConfidenceInterval getConfidenceInterval(final double volatility, final double confidenceLevel, final int n) {
    _chiSquare = new ChiSquareDistribution(n - 1);
    final double alpha = 1 - confidenceLevel;
    final double lower = volatility * Math.sqrt((n - 1) / _chiSquare.getInverseCDF(1 - alpha / 2));
    final double upper = volatility * Math.sqrt((n - 1) / _chiSquare.getInverseCDF(alpha / 2));
    return new ConfidenceInterval(volatility, lower, upper, confidenceLevel);
  }

}