A ‘grand unification’ theory assumed the existence at very high energies of a symmetry larger than SU(2) ⊗ U(1), namely SU(5). A prediction of the theory, which was experimentally proved to be false, was the value of the weak angle, sin²θ_W = 3/8. Find the partial widths of the Z in this hypothesis. Find the value of Γ_μμ/Γ_h.