| Spread WinRT Documentation > Formula Reference > Formula Functions > WEIBULL | 
This function returns the two-parameter Weibull distribution, often used in reliability analysis.
WEIBULL(x,alpha,beta,cumulative)
This function has these arguments:
| Argument | Description | 
|---|---|
| x | Value at which to evaluate the distribution | 
| alpha | Scale parameter of the distribution, represented by alpha | 
| beta | Shape parameter of the distribution, represented by beta | 
| cumulative | Logical value that determines the form of the function If cumulative is TRUE, then this function returns the cumulative distribution function; if FALSE, it returns the probability mass function. | 
Accepts numeric data for all arguments except cumulative, which is logical (boolean). Returns numeric data.
WEIBULL(3,D4,D5,FALSE)
WEIBULL(50,10,20,TRUE)