As in Fig. 8, but applying the correction factor |$f_{\Delta \nu } = (\Delta \nu _{\mathrm{obs}}/\sqrt{\rho _{\mathrm{surf}}})$| and |$f_{\nu _{\mathrm{max}}}$|⁠. The corresponding model for each star was obtained from interpolating the observed |$\Delta \nu$| into the isochrone’s surface corrected |$\Delta \nu$| sequence. Additionally, a red-clump-specific correction factor |$f_{\nu _{\mathrm{max}}} = 1.0477$| has been applied. The mean red giant and mean red clump values from the four different equations show excellent agreement among them.