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  |  | #REDIRECT [[Template:WebNotes/Weibull%2B%2BStandard_Folio_Data_Lognormal]]  | 
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 | The lognormal distribution is commonly used to model the lives of units whose failure modes are of a fatigue-stress nature. It has an increasing failure rate behavior and then decreasing towards the end of life. 
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 | The lognormal distribution is a two-parameter distribution with parameters  <br> 
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 | <math>{\mu }'</math>  and  <math>{{\sigma }_{{{T}'}}}</math>. <br> The ''pdf'' is given by: 
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 | ::<math>f({T}')=\frac{1}{{{\sigma }_{{{T}'}}}\sqrt{2\pi }}{{e}^{-\tfrac{1}{2}{{\left( \tfrac{{{T}^{\prime }}-{\mu }'}{{{\sigma }_{{{T}'}}}} \right)}^{2}}}}</math>
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 | <br> where, 
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 | <br><math>{T}'=\ln (T)</math> and
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 | <br><math>\mu' \text{ and } \sigma_{T'}</math>\
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 | are the mean and standard deviation of of the natural logarithms of the times-to-failure.
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 | | align="center" valign="middle" | [http://www.reliawiki.com/index.php/The_Weibull_Distribution Get More Details...]
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 | | align="center" valign="middle" | [http://www.reliawiki.com/index.php/Weibull_Examples_2P See Examples...]
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