Hδ_A vs Fe4383. Left: observed Hδ_A vs Fe4383. Middle: predicted Hδ_A vs Fe4383. Right: perturbed model values according to the individual observed errors. The galaxies are color-coded with log σ_⋆ from the LEGA-C DR3 catalog. The SSP model grid is shown as red (age) and blue (metallicity) lines. The statistics of the scatter and the Spearman’s rank correlation coefficient (ρ) are shown in the bottom left corner of each panel. The median uncertainties of each axis are shown in the top right corner of each panel.