Tag Archives: lognormal

Use Lognormal Distribution

The lognormal distribution has two parameters, μ and σ. These are not the same as mean and standard deviation, which is the subject of another post, yet they do describe the distribution, including the reliability function.

\displaystyle R(t)=1-\Phi \left( \frac{\ln (t)-\mu }{\sigma } \right)

Where Φ is the standard normal cumulative distribution function, and t is time. Continue reading Use Lognormal Distribution