Probability density as function of slope value of high-mass end of the CMF for (a) the global CMF in W33-Main, and (b) and (c) the prestellar and protostellar sub-populations of scenario A. The coloured histograms result from a bootstrap procedure including using the Alstott et al. (2014) method. The best slope value estimate, its uncertainty, and the starting point of the fit were determined by an exponentially modified Gaussian (EMG) (red dashed line). The 1σ errors (represented as vertical back-dashed lines) were determined by taking 68% of the slope values before and after the peak of the distribution. The Salpeter slope is represented by a purple-dashed line.