Potential Difference Help

Here is the question:
A parallel-plate capacitor is made of two circular plates, each with a diameter of .0025m. The plates of this capcitor are separated by a space of .00014m. What is the potential difference between a point midway between the plates and a point that is .00011m from one of the plates?

$$\Delta V = 3.4 * 10^{-2} V$$
$$\delta V= \frac {\Delta PE} {q}= -E \Delta d$$
$$\delta PE = -qE \Delta d = k_{c} \frac {q_{1} q_{2} } {r}$$