F2 is usually calculated as follows: F 2 = N u m b e r o f file a i l e d t e s t s T o t a l n u m b e r o file t e s t s × one hundred (twelve) https://zaneeu7d0.tkzblog.com/30975630/new-step-by-step-map-for-how-to-clean-sewage-in-qassim