We denote that the level scheme of the transitional nuclei (128-140)Nd also presents the characteristic X (5) pattern, not only in the ground-state band, but also in some low-lying bands. An adequate point of the model leading to the X (5) symmetry is therefore confirmed. We also carry out calculations of positive-parity states of even-mass Nd nuclei within the framework of the interacting-boson model, and then the calculated energy values are compared with the experimental data along with the Davidson potential predictions. By comparing transitional behavior in the Nd nuclei with the predictions of an X (5) critical symmetry, we investigate an achievable degree of agreement between the predictions of the model leading to this symmetry and the interacting-boson model (IBM-1 and IBM-2). They agree well with the predictions of the experimental data.