  Based on quantitative complementarity relations (QCRs), we analyze the
multipartite correlations in four-qubit cluster-class states. It is proven
analytically that the average multipartite correlation $E_{ms}$ is entanglement
monotone. Moreover, it is also shown that the mixed three-tangle is a
correlation measure compatible with the QCRs in this kind of quantum states.
More arrestingly, with the aid of the QCRs, a set of hierarchy entanglement
measures is obtained rigorously in the present system.
