A.1. Continuous Distributions
A.1.1. Normal
![]()
Mean = µ
Variance = σ2
Parameters:
µ: mean, ![]()
σ: standard
deviation,![]()
A.1.2. Student’s t

Mean = 0
Variance = n/(n-2), n > 2
where X has a standard normal distribution. Mean and standard deviation parameters are needed if X has a non-standard normal distribution.
Parameters:
µ: mean,![]()
σ: standard
deviation, ![]()
n: degrees of freedom, ![]()
A.1.3. Chi-Square
![]()
Mean = n
Variance = 2n
Parameter:
n: degrees of freedom, ![]()
A.1.4. F
![]()
Mean = q/(q-2), q > 2
Variance = 2q2(p+q-2)/p(q-2)2(q-4), q > 4
Parameters:
p: numerator degrees of
freedom, ![]()
q: denominator degrees of freedom, ![]()
A.1.5. Beta
![]()
Mean = α/(α+β)
Variance = αβ/((α+β)2(α+β+1))
Parameters:
α: alpha, ![]()
β: beta, ![]()
A.1.6. Gamma
![]()
Mean = αβ
Variance = αβ2
Parameters:
α: alpha shape, ![]()
β: beta scale, ![]()
A.1.7. Uniform
![]()
Mean = (M+N)/2
Variance = (N-M)2/12
Parameters:
M: lower bound
N: upper bound, ![]()
A.1.8. Triangular
![]()
Mean = (M+O+N)/3
Variance = (M2+O2+N2-MO-MN-ON)/18
Parameters:
M: lower bound
O: centre
N: upper bound, ![]()
A.1.9. Lognormal

Mean = Exp(µ+σ 2/2)
Variance = Exp(2µ+σ 2)(Exp(σ 2)-1)
Parameters:
µ: mean, ![]()
σ: standard
deviation, ![]()
A.1.10. Exponential
![]()
Mean = 1/β
Variance = 1/β2
Parameter:
β: 1/mean, ![]()
A.1.11. Erlang
![]()
Mean = 1/β
Variance = α/β2
Parameters:
α: alpha shape, ![]()
β: beta scale, ![]()
A.1.12. Weibull
![]()
Mean = (1/β)1/a G(1+1/α)
Variance = β–2/a [G(1+2/α)-G2(1+1/α)]
Parameters:
α: alpha shape, ![]()
β: beta, ![]()
