Fractional difference of the fitted temperature from the log-normal central temperature kT₀ from the toy models and the 84 clusters from the simulation. The bands show the range of values for the four different combinations of redshift and abundance from the toy models described in Sect. 3.1. The points show the values computed from the clusters, where lnkT₀ and lnσ were computed using sample means and variances weighted by the emission measure of the SPH particles. The points are color-coded according to the value of lnσ they are closest to (within Δlnσ = 0.1).