Universality of critical behavior in gases

$P-V-T$ data in the critical region of six fluids (${}_{}{}^3{}_{}{}^{}\mathrm{He}$, ${}_{}{}^4{}_{}{}^{}\mathrm{He}$, Xe, ${\mathrm{O}}_2$, C${\mathrm{O}}_2$, and ${\mathrm{H}}_2$O) have been analyzed in terms of two scaled equations of state using the methods of statistical analysis. The results confirm the hypothesis of universality of critical behavior for these gases to within the current experimental accuracy. The results also support the validity of hyperscaling relations between thermodynamic and correlation function exponents for gases. Using the hypothesis of universality we then present critical-region parameters for fourteen fluids in terms of a universal equation of state.