Yes, the question is answerable, but the answer depends on how we define redshift distance. If it means comoving distance, then the ratio to luminosity distance is simply (1+z) in a flat universe. If instead, we use the linear Hubble law D=cz/H₀​, this ratio only holds approximately at low redshift. Caveats include assumptions of a flat FLRW cosmology, negligible peculiar velocities, and no strong lensing. Also at high z, cosmological parameters (Ωₘ, Ω_Λ, etc.) start to matter. So yes, the ratio exists, but only with clearly defined terms and context.