Possibility mean, variance and covariance of triangular intuitionistic fuzzy numbers

Triangular intuitionistic fuzzy numbers (TIFNs) are a special kind of intuitionistic fuzzy sets (IFSs) on the real number set. TIFNs are useful to deal with ill-known quantities in decision data and decision making problems themselves. How to measure the value and uncertainty of a TIFN is of great importance. In this paper, we introduce the concepts of the weighted possibility mean, variance and covariance of TIFNs. Furthermore, we show that the weighted possibility mean and the weighted possibility variance of linear combination of TIFNs can be computed in a similar manner to those in probability theory. The desirable properties for the possibility covariance of TIFNs are also investigated. The concepts of the weighted possibility mean, variance and covariance of TIFNs can be considered as a generalization of those of the triangular fuzzy numbers.