Calculate the compressibility factors $z,$ and estimate $H^R$ and $S^R$ for a binary mixture propane$(1)/$methylbromide$(2)$ at $T=297K$ and $P=5$ bar for the following compositions $y_1=0\mathrm{.}25,y_1=0\mathrm{.}5,$ and $y_1=0\mathrm{.}75$ using the virial equation of state truncated after the second term. The second virial coefficients are: