Weibull Distribution

Parameters

Domain

Three-Parameter Weibull Distribution

Probability Density Function

Cumulative Distribution Function

Two-Parameter Weibull Distribution

Probability Density Function

Cumulative Distribution Function

Worksheet and VBA Functions

The following worksheet and VBA functions are available for this distribution:

Description	VBA Functions	Worksheet Functions
Distribution Fitting	-	=DistFit("Weibull";Data;[Options]1)
Probability Density Function	WeibullPdf(x,alpha,beta,[gamma])	=WeibullPdf(alpha;beta;[gamma]) =DistPdf("Weibull(alpha;beta;[gamma])";x)
Cumulative Distribution Function	WeibullCdf(x,alpha,beta,[gamma])	=WeibullCdf(alpha;beta;[gamma]) =DistCdf("Weibull(alpha;beta;[gamma])";x)
Survival Function	WeibullSurv(x,alpha,beta,[gamma])	=DistSurv("Weibull(alpha;beta;[gamma])";x)
Hazard Function	WeibullHaz(x,alpha,beta,[gamma])	=WeibullHaz(alpha;beta;[gamma]) =DistHaz("Weibull(alpha;beta;[gamma])";x)
Cumulative Hazard Function	WeibullCumHaz(x,alpha,beta,[gamma])	=DistCumHaz("Weibull(alpha;beta;[gamma])";x)
Inverse CDF (Quantile Function)	WeibullInv(P,alpha,beta,[gamma])	=WeibullInv(alpha;beta;[gamma]) =DistInv("Weibull(alpha;beta;[gamma])";P)
Random Numbers	WeibullRand(alpha,beta,[gamma])	=WeibullRand(alpha;beta;[gamma]) =DistRand("Weibull(alpha;beta;[gamma])")
Mode	WeibullMode(alpha,beta,[gamma])	=DistMode("Weibull(alpha;beta;[gamma])")
Mean	WeibullMean(alpha,beta,[gamma])	=WeibullMean(alpha;beta;[gamma]) =DistMean("Weibull(alpha;beta;[gamma])")
Variance	WeibullVar(alpha,beta,[gamma])	=WeibullVar(alpha;beta;[gamma]) =DistVar("Weibull(alpha;beta;[gamma])")
Standard Deviation	WeibullStdev(alpha,beta,[gamma])	=WeibullStdev(alpha;beta;[gamma]) =DistStdev("Weibull(alpha;beta;[gamma])")
Skewness	WeibullSkew(alpha,beta,[gamma])	=DistSkew("Weibull(alpha;beta;[gamma])")
(Excess) Kurtosis	WeibullKurt(alpha,beta,[gamma])	=DistKurt("Weibull(alpha;beta;[gamma])")

1. The Options parameter is optional. Possible options: "gamma=value"  (example: "gamma=0")
2. The gamma parameter is optional (the default value is 0).