In this paper, the method based on Fuzzy Expectation proposed by Kang et al. (2012) is
employed to transform the theorem of a Z-number to a classical fuzzy number. This theorem is
briefly described in the following paragraphs.
Definition: A fuzzy set (A) is defined as: =
;
))| ∈ , where the membership
function A is shown by : → [0; 1]. The expected value of a fuzzy set can be shown as follows: