This final analysis of hadronic and leptonic cross-sections and of leptonic
forward-backward asymmetries in e(+)e(-) collisions With the OPAL detector
makes use of tile full LEP 1 data sample comprising 161pb(-1) of integrate
d luminosity and 4.5 x 10(6) selected Z decays. An interpretation of the da
ta in terms of contributions from pure Z exchange and from gamma /Z interfe
rence allows the parameters of tile Z resonance to be determined in a model
-independent way. Our results are in good agreement with lepton universalit
y anti consistent with the vector and axial-vector couplings predicted in t
he Standard Model. A fit to the complete dataset yields the fundamental Z r
esonance parameters: m(z) = (91.1852 +/- 0.0030) GeV. Gamma (Z) = 12.4948 /- 0.0041) GeV. sigma (0)(h) = (41.501 +/- 0.055) nb. R-l = 20.823 +/- 0.04
4, and A(FB)(0,l) = 0.0145 +/- 0.0017. Transforming these parameters gives
a measurement of the ratio between the decay width into invisible particles
and the width to a single species of charged lepton. Gamma (inv)/Gamma (ll
) = 5.942 +/- 0.027. Attributing the entire invisible width to neutrino, de
cays and assuming tile Standard Model couplings for neutrinos. this transla
tes into a measurement of the effective number of light neutrino species. N
-nu = 2.984 +/- 0.013. Interpreting the data within the context of the Stan
dard Model allows the mass of the top quark, m(t) = (162(-16)(+29)) GeV, to
be determined through its influence oil radiative corrections. Alternative
ly, utilising the direct external measurement of m(t) as an additional cons
traint leads to a measurement of the strong coupling constant and the mass
of the Higgs boson: alpha (s)(m(Z)) = 0.127 +/- 0.005 and m(H) = (390(-280)
(+750)) GeV.