  Relations between the observed quantities for a beamed radio jet, apparent
transverse speed and apparent luminosity (beta_app,L), and the intrinsic
quantities, Lorentz factor and intrinsic luminosity (gamma,L_o), are
investigated. The inversion from measured to intrinsic values is not unique,
but approximate limits to gamma and L_o can be found using probability
arguments. Roughly half the sources in a flux density--limited, beamed sample
have a value of gamma close to the measured beta_app. The methods are applied
to observations of 119 AGN jets made with the VLBA at 15 GHz during 1994-2002.
The results strongly support the common relativistic beam model for an
extragalactic radio jet. The (beta_app,L) data are closely bounded by a
theoretical envelope, an aspect curve for gamma=32, L_o= 10^25 W/Hz. This gives
limits to the maximum values of gamma and L_o in the sample: gamma_max about
32, and L_o,max ~ 10^26 W/Hz. No sources with both high beta_app and low L are
observed. This is not the result of selection effects due to the observing
limits, which are flux density S>0.5 Jy, and angular velocity mu<4 mas/yr. Many
of the fastest quasars have a pattern Lorentz factor gamma_p close to that of
the beam, gamma_b, but some of the slow quasars must have gamma_p<<gamma_b.
Three of the 10 galaxies in the sample have a superluminal feature, with speeds
up to beta_app about 6. The others are at most mildly relativistic. The
galaxies are not off-axis versions of the powerful quasars, but Cygnus A might
be an exception.
