F ( c ) = 1 − e − x b    ∑ k = 0  c − 1   ( x b   )   k   k !           ( 1 )    MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaacqWGgbGrcqGGOaakcqWGJbWycqGGPaqkcqGH9aqpcqaIXaqmcqGHsislcqWGLbqzdaahaaWcbeqaaiabgkHiTmaalaaabaGaemiEaGhabaGaemOyaigaaaaakmaaqahabaWaaSaaaeaadaqadaqaamaalaaabaGaemiEaGhabaGaemOyaigaaaGaayjkaiaawMcaamaaCaaaleqabaGaem4AaSgaaaGcbaGaem4AaSMaeiyiaecaaaWcbaGaem4AaSMaeyypa0JaeGimaadabaGaem4yamMaeyOeI0IaeGymaedaniabggHiLdGccaWLjaGaaCzcamaabmaabaGaeGymaedacaGLOaGaayzkaaaaaa@4DA8@