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
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If x, alpha, or beta is nonnumeric, WEIBULL returns the #VALUE! error value.
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If x < 0, WEIBULL returns the #NUM! error value.
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If alpha ≤ 0 or if beta ≤ 0, WEIBULL returns the #NUM! error value.
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The equation for the Weibull cumulative distribution function is:
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The equation for the Weibull probability density function is:
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When alpha = 1, WEIBULL returns the exponential distribution with:
Examples
X |
Alpha |
Beta |
Formula |
Description (Result) |
---|---|---|---|---|
105 |
20 |
100 |
=WEIBULL([X],[Alpha],[Beta],TRUE) |
Weibull cumulative distribution function for the specified arguments (0.929581) |
105 |
20 |
100 |
=WEIBULL([X],[Alpha],[Beta],FALSE) |
Weibull probability density function for the specified arguments (0.035589) |