  We use the PSCz IRAS galaxy redshift survey to analyze the cosmological
galaxy dipole out to a distance 300 h$^{-1}$ Mpc. The masked area is filled in
three different ways, firstly by sampling the whole sky at random, secondly by
using neighbouring areas to fill a masked region, and thirdly using a spherical
harmonic analysis. The method of treatment of the mask is found to have a
significant effect on the final calculated dipole.
  The conversion from redshift space to real space is accomplished by using an
analytical model of the cluster and void distribution, based on 88 nearby
groups, 854 clusters and 163 voids, with some of the clusters and all of the
voids found from the PSCz database.
  The dipole for the whole PSCz sample appears to have converged within a
distance of 200 $h^{-1}$Mpc and yields a value for $\beta = \Omega^{0.6}/b$ =
0.75 (+0.11,-0.08), consistent with earlier determinations from IRAS samples by
a variety of methods. For b = 1, the $2-\sigma$ range for $\Omega_{o}$ is
0.43-1.02.
  The direction of the dipole is within 13$^o$ of the CMB dipole, the main
uncertainty in direction being associated with the masked area behind the
Galactic plane. The improbability that further major contributions to the
dipole amplitude will come from volumes larger than those surveyed here means
that the question of the origin of the CMB dipole is essentially resolved.
