Logarithm of the soft‐band X‐ray–to–optical ratio, ﹩\mathrm{log}\,\,( L^{s}_{\mathrm{X}\,}/L_{B}) ﹩, vs. the logarithm of the hard‐band ratio, ﹩\mathrm{log}\,\,( L^{h}_{\mathrm{X}\,}/L_{B}) ﹩, for all 61 galaxies in our survey. The solid lines show the best‐fit linear relations for group 1, groups 2 and 3, and group 4 galaxies. In the case of group 1 galaxies, NGC 5102 was excluded from this fit. The dotted line is the best‐fit relation for group 1 galaxies if NGC 5102 is included. Symbols with one‐sided vertical arrows were detected in the hard band only, and symbols with one‐sided slanted arrows were not detected in either band. The bulges of M31 and NGC 1291 are shown as a filled and open hexagon, respectively.