Answer
$k=4.6$
Work Step by Step
We can find the dielectric constant k as follows:
$k=\frac{d}{\epsilon_{\circ}A}\frac{Q}{V}$
We plug in the known values to obtain:
$k=\frac{(0.25\times 10^{-3})(1.2\times 10^{-6})}{(8.85\times 10^{-12})\pi(0.056)^2(750)}$
$k=4.6$
