Log-normal distribution

GPTKB entity

Statements (40)
Predicate Object
gptkbp:instanceOf Probability distribution
gptkbp:affiliatedWith continuous probability distributions
gptkbp:alsoKnownAs gptkb:lognormal_distribution
gptkbp:application modeling income distribution
modeling stock prices
modeling particle sizes
modeling biological measurements
gptkbp:category distributions with positive support
right-skewed distributions
gptkbp:characteristic does not have a simple closed form
gptkbp:compatibleWith symmetric
gptkbp:cumulativeDistributionFunction F(x; μ, σ) = 0.5 + 0.5 erf[(ln x - μ)/(σ√2)]
gptkbp:definedIn a probability distribution of a random variable whose logarithm is normally distributed
gptkbp:describedYear 1879
gptkbp:entropy μ + 0.5 + ln(σ√(2π))
gptkbp:firstDescribed gptkb:Francis_Galton
gptkbp:heldBy positively skewed
https://www.w3.org/2000/01/rdf-schema#label Log-normal distribution
gptkbp:kurtosis exp(4σ^2) + 2exp(3σ^2) + 3exp(2σ^2) - 6
gptkbp:meaning exp(μ + σ^2/2)
gptkbp:medium exp(μ)
gptkbp:mode exp(μ - σ^2)
gptkbp:momentGeneratingFunction does not exist for all t
gptkbp:originatedIn multiplicative processes
gptkbp:parameter μ (mean of log), σ (standard deviation of log)
gptkbp:probabilityDensityFunction f(x; μ, σ) = (1/(xσ√(2π))) exp(-(ln x - μ)^2/(2σ^2)), x > 0
gptkbp:relatedTo gptkb:Weibull_distribution
gptkb:Exponential_distribution
gptkb:Gamma_distribution
gptkb:Normal_distribution
gptkbp:skewness (exp(σ^2) + 2)√(exp(σ^2) - 1)
gptkbp:supports x > 0
gptkbp:usedIn biology
environmental science
finance
hydrology
reliability engineering
gptkbp:variant [exp(σ^2) - 1] exp(2μ + σ^2)
gptkbp:bfsParent gptkb:Log-gamma_distribution
gptkbp:bfsLayer 7