What is the pH of the solution after 28.0 mL of the KOH solution have been added to the HF solution?

A 0.270 M solution of HF (40.0 mL) was titrated with a 0.410 M KOH solution. What is the pH of the solution after 28.0 mL of the KOH solution have been added to the HF solution? [Ka (HF) = 4.5 x 10-4]