A flask holds $240\ \text{mL}$ of a solution made by dissolving $0.00300\ \text{mol}$ of trimethylamine in water at 298 K. Trimethylamine has $\text{p}K_b = 4.22$. Take $K_w = 1.0 \times 10^{-14}$ and use the full quadratic expression. What is the pH of the solution?