  We study some observational consequences of a recently proposed
scale--dependent cosmological model for an inhomogeneous Universe. In this
model the Universe is pictured as being inside a highly dense and rapidly
expanding shell with the underdense center. For nearby objects ($z \ll 1$), the
linear Hubble diagram is shown to remain valid even in this model, which has
been demonstrated both analytically and numerically. For large $z$, we present
some numerical results of the redshift--luminosity distance relation and the
behavior of the mass density as a function of the redshift. It is shown that
the Hubble diagram in this model for a locally $open$ Universe ($\Omega(t_0, r
\sim 0)=0.1$) resembles that of the $flat$ Friedmann cosmology. This implies
that study of the Hubble diagram cannot uniquely determine the value of $q_0$
or $\Omega_0$ in a model--independent way. The model also accounts for the fact
that $\Omega_0$ is an increasing function of the redshift.
