Left: scaling relation between Planck SZ measurements and X-ray luminosity for  ~1600 MCXC clusters. Individual measurements are shown by the black dots and the corresponding bin averaged values by the red diamonds. Thick bars give the statistical errors, while the thin bars are bootstrap uncertainties. The bin-averaged SZ cluster signal expected from the X-ray based model is shown by the blue stars. The combination of the adopted – M₅₀₀ and L₅₀₀ – M₅₀₀ relations (Eq. (6)) is shown by the dashed blue line while the red dot-dashed line shows the best fitting power-law to the data (Eq. (7) and Table 4). Right: ratio between data and model bin averaged values shown in the left panel. Error bars are as in the left panel.