Posterior PDFs of intrinsic lengths for a given projected length L | L_p = l_p. If tail index ξ is known, then an RG’s l_p fixes the probability distribution over its possible l. This distribution is strongly skewed, and the same for all l_p – save for horizontal translation and vertical scaling. We illustrate this point by showing posterior PDFs for giants with two different l_p. Top: l_p = 1 Mpc. Bottom: l_p = 5 Mpc. For ξ = −4, the posterior mean 𝔼[L | L_p = l_p] = 1.13 l_p and the posterior standard deviation (see Table 1).