If 55.0 mL of ethanol {rm{(density}} = 0.789;{rm{g}}/{{rm{mL}}})) initially at 9.0^circ C is mixed with 55.0 mL of water {rm{(density}} = 1.0;{rm{g}}/{{rm{mL}}}) initially at 28.1^circ C in an insulated beaker, and assuming that no heat is lost, what is the final temperature of the mixture?