Notes on possibilistic variances of fuzzy numbers

Abstract The definitions of two crisp possibilistic variances of a fuzzy number A , Var ( A ) and Var ′ ( A ) , were introduced by Carlsson and Fuller. In this work, we show that many properties of variance in probability theory are preserved by Var ′ ( A ) . We also get the important relationships between Var ( A ) and Var ′ ( A ) .