Template:Normal probability density function

Normal Probability Density Function
The $$pdf$$  of the normal distribution is given by:


 * $$f(t)=\frac{1}{\sigma \sqrt{2\pi }}{{e}^{-\frac{1}{2}{{\left( \frac{t-\mu }{\sigma } \right)}^{2}}}}$$

where:

$$\mu$$ = mean of the normal times-to-faiure, also noted as $$\bar{T}$$,

$$\theta=\text{standard deviation of the times-to-failure} $$

It is a two-parameter distribution with parameters $$\mu $$  (or  $$\bar{T}$$ ) and  $$$$, i.e. the mean and the standard deviation, respectively.