A medium is divided into regions I and II about x = 0 plane, as shown in the figure below. An electromagnetic wave with electric field $${\overrightarrow E _1} = 4{{\hat a}_x} + 3{{\hat a}_y} + 5{{\hat a}_z}$$     is incident normally on the interface from region-I. The electric field $${\overrightarrow E _2}$$ in region-II at the interface is