Scaled entropy profile of UGC 03957. The green dot-dashed line shows the entropy profile estimated from the deprojected temperature and density profiles. The red solid line represents the profile corrected for the gas mass fraction as suggested by Pratt et al. (2010) (Eq. (10)). Dotted and dashed lines represent the predictions from gravitational structure formation simulations by Voit (2005) and correspond to Eqs. (7) and (9), respectively.