Results for measuring the observed biweight-midvairance dispersion from 10,000 resamples of the vD18b data set. Here, the original velocities are perturbed within their 1σ uncertainties as described in the text. The mean observed biweight for the sample comes out as ﹩{\sigma }_{\mathrm{obs},\mathrm{bi}}=14.3\pm 3.5\,\mathrm{km}\,{{\rm{s}}}^{-1}﹩, giving ﹩{\sigma }_{\mathrm{int},\mathrm{bi}}=12.0\pm 2.5\,\mathrm{km}\,{{\rm{s}}}^{-1}﹩, higher than the 90% upper limit from vD18b, and consistent with our MCMC analysis.