Dimethylammonium acetate is a salt formed from a weak acid (acetic acid) and a weak base (dimethylamine). For a salt of a weak acid and a weak base, the pH of its aqueous solution is calculated using the formula: $\text{pH} = 7 + \frac{1}{2}(\text{p}K_a - \text{p}K_b)$

Given: $\text{p}K_a = 4.77$ $\text{p}K_b = 3.27$

Substituting the given values into the formula: $\text{pH} = 7 + \frac{1}{2}(4.77 - 3.27)$ $\text{pH} = 7 + \frac{1}{2}(1.50)$ $\text{pH} = 7 + 0.75 = 7.75$

Therefore, the pH of the dimethylammonium acetate solution is $7.75$ .