The following formula gives the asymptotic standard deviation, i.e. the robust estimate of the variability of the data under consideration, where N is the number of observations and IQR the interquartile range, which covers exactly 50 % of the cases of any probability distribution.
Järgmine valem tähistab asümptootilist standardhälvet st asjaomaste andmete varieeruvuse robustset hinnangulist väärtust, milles N on vaatluste arv ja IQR on kvartiilhaare, mis hõlmab täpselt 50 % mingi jaotuse juhtudest.