Absolute magnitude of 10 μm vs. log(L₄₀₀₀) for (a) the whole QSO sample, (b) the RQQs, and (c) the RLQs. The blue dots are the tQSOs, and the red dots are the rQSOs. The blue line and the red line are the linear χ² fitting of the tQSOs and the rQSOs, respectively. The blue shadow and the red shadow in each figure are the 95% confidence intervals of the tQSOs and the rQSOs, respectively. Note that the confidence intervals are too small to be easily visible for (a) and (b), but is still visible for (c).