Normalized histograms showing the distribution of SMBH mass ratio q_• (Equation (12)) calculated from inferred quantities M_•−M﹩{}_{{\rm{b}},{\rm{\inf }}}﹩ (Equations (8) and (9)) and M_•–σ_inf (Equation (11)) in light blue and M_•–M_b and M_•–σ in dark blue. Panels (a) and (c) use the N. J. McConnell & C.-P. Ma (2013) scaling relations and panels (b) and (d) use the J. Kormendy & L. C. Ho (2013) relations. The solid black line at q_• = 0.25 divides major and minor SMBH mergers, and the relative fractions of major (f_major) and minor (f_minor) SMBH mergers predicted by each scaling relation are shown as percentages of the total close-pair sample. The K-S test statistic and p-values between the light and dark blue distributions are shown in the upper-right corners of each panel. M_•−M﹩{}_{{\rm{b}},{\rm{\inf }}}﹩ predicts a greater fraction of major SMBH mergers than M_•–M_b, while M_•–σ_inf predicts a greater fraction of minor mergers than M_•–σ.