The expected value of F is  (where  is the treatment sample size) which is 1 for no treatment effect.
ðɪ ɛkspˈɛktᵻd vˈæljuː ʌv ˈɛf ɪz wˌɛɹ ɪz ðə tɹˈiːtmənt sˈæmpəl sˈaɪz wˌɪtʃ ɪz wˈʌn fɔːɹ nˈoʊ tɹˈiːtmənt ɪfˈɛkt.