Compatibility - WEIBULL Function

The WEIBULL function replaces the WEIBULL.DIST function in Excel 2010.

Description

The function 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)

Arguments

Argument Description Required/ Optional
X The value at which to evaluate the function. Required
Alpha A parameter to the distribution. Required
Beta A parameter to the distribution. Required
Cumulative Determines the form of the function. Required

Notes

  • The equation for the Weibull cumulative distribution function is −

    $$F(x;\alpha,\beta) = 1-e^{-(x/\beta)^\alpha}$$

  • The equation for the Weibull probability density function is−

    $$f(x;\alpha,\beta) = \frac{\alpha}{\beta^\alpha}x^{\alpha-1}e^{-(x/\beta)^\alpha} $$

  • When alpha = 1, WEIBULL returns the exponential distribution with−

    $$\lambda = \frac{1}{\beta}$$

  • 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.

Example

WEIBULL Function
advanced_excel_compatibility_functions.htm
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