How is the conditional formation constant (K'ₒ) calculated in an EDTA titration?

By multiplying the fraction of EDTA in its basic form by the stability constant.

By dividing the stability constant by the fraction of EDTA in its basic form.

By adding the fraction of EDTA in its basic form to the stability constant.

By subtracting the fraction of EDTA in its basic form from the stability constant.