Left panel: PAH-to-dust mass fraction (q_PAH) versus 15 μm (F1500W) to 25.5 μm (F2550W) flux ratios for a sample of z = 0.7 − 0.9 galaxies with significant (> 3σ) detections in F1500W and F2550W. q_PAH is derived from PROSPECTOR (the Draine & Li 2007 models), while the flux ratio is an empirical tracer of PAH to warm dust emission, as is shown in the right panel. The significant linear correlation of the two quantities (Pearson correlation coefficient of 0.71 with p-value = 0.001) indicates the validity of the estimated q_PAH values. Right panel: Two mid-IR spectra with a high PAH fraction (solid) and low PAH fraction (dashed), overlaid with the wavelength coverage of the F1500W and F2550W filters at z = 0.7 − 0.9. In this redshift range, F1500W and F2550W filters trace the PAH dominated and non-PAH-dominated dust emission in star-forming galaxies, respectively. Therefore, their ratio is expected to correlate with PAH fraction.