We use $A, B, C, D, E$ to represent Amy, Bob, Carla, Dan, and Eric, respectively. We use the greater than symbol $(>)$ to represent 'is taller than' and the less than symbol $(<)$ to represent 'is shorter than'. From the first bullet, $A > C$. From the second bullet, $D < E$ and $D > B$ so $E > D > B$. From the third bullet, $E < C$ or $C > E$. Since $A > C$ and $C > E$ and $E > D > B$, then $A > C > E > D > B$, which means that Bob is the shortest.