An analytical chemist weighs out 0.265g of an unknown triprotic acid into a 250mL volumetric flask and dilutes to the mark with distilled water. She then titrates this solution with 0.0600M NaOH solution. When the titration reaches the equivalence point, the chemist finds she has added 69.0mL of NaOH solution. Calculate the molar mass of the unknown acid. Round your answer to 3 significant digits.