$pH\,=\,\frac{p{{K}_{1}}\,+\,p{{K}_{2}}}{2}\,=\,\frac{1.88\,+\,3.65}{2}$

$=\frac{5.53}{2}\,=\,2.675\,\approx \,2.77$

At isoelectric point of aspartic acid both carboxylic as well as amino form co-exist.