A slab of material of dielectric constant K = 5 has the same area as the plates of a parallel plate capacitor but has a thickness $\frac{3}{4}d$ , [Where d is the separation between the plates] is inserted between the plates, then the capacitance of the capacitor becomes $\frac{x{c}_0}{2}$ ($c_0$ = capacitance without di-electric). Find x ?