Mean and Variance of the Beta Distribution

Formula: \(\mu = \frac{\alpha}{\alpha + \beta}\) \(\mathrm{Var}(X) = \frac{\alpha \cdot \beta}{(\alpha + \beta)^2 (\alpha + \beta + 1)}\)

mbeta(shape1, shape2)

Arguments

shape1

Alpha parameter

shape2

Beta parameter

Value

List with mean and variance

References

Johnson, N.L., Kotz, S., and Balakrishnan, N. (1995). Continuous Univariate Distributions, Vol. 2. Wiley.

See also

dbeta

Examples

mbeta(shape1 = 2, shape2 = 3)
#> $mean
#> [1] 0.4
#> 
#> $variance
#> [1] 0.04
#>