  Production of events with hadronic and leptonic final states has been
measured in e^+e^- collisions at centre-of-mass energies of 130-172 GeV, using
the OPAL detector at LEP. Cross-sections and leptonic forward-backward
asymmetries are presented, both including and excluding the dominant production
of radiative Z \gamma events, and compared to Standard Model expectations. The
ratio R_b of the cross-section for bb(bar) production to the hadronic
cross-section has been measured. In a model-independent fit to the Z lineshape,
the data have been used to obtain an improved precision on the measurement of
\gamma-Z interference. The energy dependence of \alpha_em has been
investigated. The measurements have also been used to obtain limits on
extensions of the Standard Model described by effective four-fermion contact
interactions, to search for t-channel contributions from new massive particles
and to place limits on chargino pair production with subsequent decay of the
chargino into a light gluino and a quark pair.
