Examples of the bulk density ρ as a function of the mass ratio q for two asteroids, (7616) Sadako (top left) and (6261) Chione (top right). The red line indicates the nominal value. Shown in grey is the error range on the density. The blue and orange horizontal lines represent physically reasonable limits. q_min1, q_max1, q_min2 and q_max2 mark the corresponding extremes of the mass ratio values. The bottom plot shows the case for (930) Westphalia, eliminated in the density filtering because the minimum estimated density is higher than the chosen range of bulk density.