A molecule has two amino/ammonium groups with pKas of 8.9 and 10.8, and a carboxyl group with a pKa of 4.1. A biochemist has 100 mL of a 0.1 M solution of this compound at a pH of 8.3. She adds 40 mL of 0.1 M HCl. What is the pH of the resulting solution? Report your answer to two figures.