  We calculate filling factors (${\varepsilon}$) and ionized masses (M$_{\rm
i}$) for a total of 84 galactic and extragalactic planetary nebulae (PNe) at
known distances. To do these calculations, we have chosen forbidden line
electron densities, observed angular diameters, and H${\beta}$ fluxes, from the
most recent measurements available in the literature. Statistical analysis on
the distributions of ${\varepsilon}$ and ${\rm M_i}$ show that (1) the ranges
of values of these parameters is wider than what was previously found; (2) the
mean value of the filling factor is between $0.3$ and $0.4$, for the different
sets; (3) the mean value of the ionized mass is between $0.1$ and $0.25$
$M_{\odot}$; (4) a clear correlation between the filling factors and the
dimensions of the PNe was not found when distance-independent sets of PNe were
used; (5) for extragalactic PNe, where distance errors are not a factor, the
filling factors and the ionized masses anticorrelate tightly with the electron
densities. The results indicate that the modified Shklowsky distance method is
correct.
