Two identical square parallel metal plates each have an area of $340c{m}^2.$ They are separated by $2\mathrm{.}20$ cm $.$ They are both initially uncharged. Now a charge of $+2\mathrm{.}20$ nc is transferred from the plate on the left to the plate on right and the charges then establish electrostatic equilibrium. $($Neglect edge effects.$)$ What is the electric field between the plates at a distance of $0\mathrm{.}25$ cm from the plate on the right?

$\frac{2\mathrm{.}2{10}^{-9}}{21}$