Statistical - WEIBULL.DIST Function



Description

The WEBULL.DIST function returns the Weibull distribution. Use this distribution in reliability analysis, such as calculating a device's mean time to failure.

Syntax

WEIBULL.DIST(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 −

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

  • The equation for the Weibull probability density function is −

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

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

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

  • If x, alpha, or beta is nonnumeric, WEIBULL.DIST returns the #VALUE! error value.

  • If x < 0, WEIBULL.DIST returns the #NUM! error value.

  • If alpha ≤ 0 or if beta ≤ 0, WEIBULL.DIST returns the #NUM! error value.

Applicability

Excel 2010, Excel 2013, Excel 2016

Example

Weibull.Dist function
advanced_excel_statistical_functions.htm
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