Mass and radius posteriors for 4U 1702−429. The left panel shows the results for model A, which has fixed S_f = 1 and X = 0. The right panel shows the results for model D, which has free X and fixed S_f = 1. The symbols and legends are the same as in Fig. 4. We recall that for our synthetic data fits (shown in Fig. 6), model A underestimates the mass slightly. For X ≠ 0 the correct mass is obtained using model D. This suggests that the true mass of 4U 1702−429 is in the range M = 1.4−2.0 M_⊙. Models A and D are both capable of recovering the radius used to construct the synthetic data, which suggests that the radius of 4U 1702−429 is R = 12.0−12.9 km at 68% credibility.