Observed values of log(M_gas) in the MAGMA sample compared to those predicted by Eq. (11) as a function of M_star, SFR, and M_HI; the regression is illustrated by the gray-dashed line. Unlike Fig. 9 and Eq. (10), here the independent variables include M_HI. The right panel shows the residuals and the Gaussian fit; the 1σ dispersion of the Gaussian is ∼0.05 dex as discussed in the text. Galaxies are colored by gas fraction as shown in previous figures.