∑ i  ( F i     2     )  ( ( F ¯  i     2     )  − S + ( F i     2     )   )    ⋅       ( 14  )    MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaadaaeqbqaamaabmGabaqbaeqabiqaaaqaaiabdAeagnaaBaaaleaacqWGPbqAaeqaaaGcbaGaeGOmaidaaaGaayjkaiaawMcaamaabmGabaWaaeWaceaafaqabeGabaaabaGafmOrayKbaebadaWgaaWcbaGaemyAaKgabeaaaOqaaiabikdaYaaaaiaawIcacaGLPaaacqGHsislcqWGtbWucqGHRaWkdaqadiqaauaabeqaceaaaeaacqWGgbGrdaWgaaWcbaGaemyAaKgabeaaaOqaaiabikdaYaaaaiaawIcacaGLPaaaaiaawIcacaGLPaaaaSqaaiabdMgaPbqab0GaeyyeIuoakiabgwSixlaaxMaacaWLjaWaaeWaceaacqaIXaqmcqaI0aanaiaawIcacaGLPaaaaaa@4B64@