Median Life

Definition

Let $T$ be Survival Time

Median life (denoted $t_{0.5}$) is the time where exactly 50% of subjects have experienced the event and 50% have not.

Interpretation

The median survival time — half the population has failed by this time, half remains.

Property

The median life satisfies:

$S(t_{0.5})=0.5$

Or equivalently:

$F(t_{0.5})=0.5$