the primativly of midium is 26.55×10c/nm the dielectric constant of the midium well be
Permittivity of the medium is 26.55x10 C²/Nm²
Dielectric constant is the ratio of permittivity of medium to permittivity of vaccum (free space).
Experimentally, permittivity of vaccum is 8.85 × 10^-12 C²/Nm².
So dielectric constant is 26.55x10/(8.85x10^-12)
= 3x10^13