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<< Click to Display Table of Contents >> WEIBULL.DIST (Weibull distribution) |
Syntax:
WEIBULL.DIST(x, Alpha, Beta, Cumulative)
Description:
This returns the probabilities of a Weibull distributed random variable.
The Weibull distribution is an extension of the exponential distribution (see function EXPON.DIST/EXPONDIST) to events that are not purely random and do not exactly match the Poisson distribution (see function POISSON.DIST/POISSON).
It is used especially for reliability analysis.
x is the value whose probability is to be calculated. x must be ≥ 0.
Alpha is a parameter of the distribution. Alpha determines the shape of the distribution curve. If Alpha = 1, the Weibull distribution equals an exponential distribution with Lambda = 1/Beta.
Beta is another parameter of the distribution. Beta determines the scaling of the distribution curve, i.e., it stretches or compresses the function graph.
Both parameters have to be greater than zero.
You use the logical value Cumulative to specify which type of function will be returned:
FALSE: The probability density function is returned.
TRUE: The cumulative distribution function is returned.
Example:
WEIBULL.DIST(42, 2, 100, TRUE) returns 0.16172
WEIBULL.DIST(42, 2, 100, FALSE) returns 0.00704
Compatibility notes:
Microsoft Excel supports this function only in version 2010 or later. The function is unknown in older versions.
See also: