  We perform a global fit of the parameters of the Standard Model with a
sequential fourth generation (SM4) to LHC and Tevatron Higgs data and
electroweak precision data. Using several likelihood ratio tests we compare the
performance of the SM4 and SM3 at describing the measured data. Since the SM3
and SM4 are not nested (i.e. the SM3 can not be considered as a special case of
the SM4 with some parameters fixed) the usual analytical formulae for p-values
in likelihood ratio tests do not hold. We thus apply a new method to compute
these p-values. For a Higgs mass of 126.5 GeV and fourth-generation quark
masses above 600 GeV we find that the SM4 is excluded at 3.1 sigma.
