  We analyze the equation of state of 2+1 flavor lattice QCD at zero baryon
density by constructing the simple quark-hadron hybrid model that has both
quark and hadron components simultaneously. We calculate hadron and quark
contribution separately and parameterizing those to match with LQCD data.
Lattice data on the equation of state are decomposed into hadron and quark
components by using the model. The transition temperature is defined by the
temperature at which the hadron component is equal to the quark one in the
equation of state. The transition temperature thus obtained is about 215 MeV
and somewhat higher than the chiral and the deconfinement pseudocritical
temperatures defined by the temperature at which the susceptibility or the
absolute value of the derivative of the order parameter with respect to
temperature becomes maximum.
