commons-statistics-distribution/src/main/java/org/apache/commons/statistics/distribution/BetaDistribution.java [193:219]:
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    @Override
    public double getMean() {
        return mean;
    }

    /**
     * {@inheritDoc}
     *
     * <p>For first shape parameter \( \alpha \) and second shape parameter
     * \( \beta \), the variance is:
     *
     * <p>\[ \frac{\alpha \beta}{(\alpha + \beta)^2 (\alpha + \beta + 1)} \].
     */
    @Override
    public double getVariance() {
        return variance;
    }

    /**
     * {@inheritDoc}
     *
     * <p>The lower bound of the support is always 0.
     *
     * @return 0.
     */
    @Override
    public double getSupportLowerBound() {
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -



commons-statistics-distribution/src/main/java/org/apache/commons/statistics/distribution/FDistribution.java [282:313]:
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    @Override
    public double getMean() {
        return mean;
    }

    /**
     * {@inheritDoc}
     *
     * <p>For numerator degrees of freedom parameter \( n \) and denominator
     * degrees of freedom parameter \( m \), the variance is:
     *
     * <p>\[ \operatorname{var}[X] = \begin{cases}
     *       \frac{2m^2 (n+m-2)}{n (m-2)^2 (m-4)} &amp; \text{for } m \gt 4 \\
     *       \text{undefined}                     &amp; \text{otherwise}
     *       \end{cases} \]
     *
     * @return the variance, or {@link Double#NaN NaN} if it is not defined.
     */
    @Override
    public double getVariance() {
        return variance;
    }

    /**
     * {@inheritDoc}
     *
     * <p>The lower bound of the support is always 0.
     *
     * @return 0.
     */
    @Override
    public double getSupportLowerBound() {
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -