[en] Recently derived data-to-data (DTD) relations have been applied to elastic and inelastic scattering of 800-MeV protons from ⁹⁰Zr and ⁹²Zr. Significant differences between the cross sections for the 2₁/sup ts+/ and 4₁/sup ts+/ states in the two nuclei suggest that DTD relations between elastic and inelastic cross sections are inadequate. Nevertheless, the DTD relation which predicts the analyzing power (A/sub y/) from the cross section for inelastic transitions yields excellent agreement with the data. The physical significance of the fitting parameters is discussed