WEIBULL
Returns the Weibull distribution. Use this distribution in reliability analysis, such as calculating a device's mean time to failure.
Syntax
WEIBULL(x,alpha,beta,cumulative)
X is the value at which to evaluate the function.
Alpha is a parameter to the distribution.
Beta is a parameter to the distribution.
Cumulative determines the form of the function.
Remarks
- If x, alpha, or beta is nonnumeric, WEIBULL returns the #VALUE! error value.
- If x < 0, WEIBULL returns the #NUM! error value.
- If alpha £ 0 or if beta £ 0, WEIBULL returns the #NUM! error value.
- The equation for the Weibull cumulative distribution function is:
- The equation for the Weibull probability density function is:
- When alpha = 1, WEIBULL returns the exponential distribution with:
Examples
WEIBULL(105,20,100,TRUE)
equals 0.929581
WEIBULL(105,20,100,FALSE)
equals 0.035589