(a) Effective averaging scales as a function of angular resolution estimated by using a median distance of 5.1 kpc and distance ranges corresponding to source percentages of 80%, 90%, and 99% of total sources. The dashed red line shows the transverse physical sizes at a distance of 5.1 kpc. (b) Estimated number of 1.1 mm sources inside one resolution element for areas covering source percentages of 80%, 90%, and 99% of total sources.