Force between the plates of a capacitor when a dielectric slab is added

Say there are two parallel plates separated by a small fixed distance d and charged +q, -q. The force attracting the plates is F. If a solid block of dielectric (dielectric constant k) is introduced between the plates, will the force of attraction be different from F.

My answer: The electric field will be reduce by a factor of 1/k; thus the force is lesser than F.
Is this answer correct?

jbriggs444