  To investigate the origin of the enhanced $T_c$ ($\approx$ 110 K) of the
trilayer cuprate superconductor Bi$_{2}$Sr$_{2}$Ca$_{2}$Cu$_{3}$O$_{10+\delta}$
(Bi-2223), we have performed systematic magnetoresistance (MR) measurements on
this superconductor, as well as on the bilayer superconductor,
Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ (Bi-2212). The in-plane coherence
length, $\xi_{ab}$, and the specific-heat jump, ${\Delta}C$, have been
estimated using the theory of renormalized superconductive fluctuations, and
the doping dependence of these parameters has been qualitatively explained
using the Fermi arc approach. A detailed comparison of the superconducting
parameters with $T_c$ for these compounds suggests that an additional
superconducting condensation energy exists, due to an increase in the number of
stacking CuO$_{2}$ planes in a unit cell.
