The book aims at surveying results in the application of fuzzy sets and fuzzy logic to economics and engineering. New results include fuzzy non-linear regression, fully fuzzified linear programming, fuzzy multi-period control, fuzzy network analysis, each using an evolutionary algorithm, fuzzy queuing decision analysis using possibility theory, fuzzy differential equations, fuzzy difference equations, fuzzy partial differential equations, fuzzy eigenvalues based on an evolutionary algorithm, fuzzy hierarchical analysis using an evolutionary algorithm, fuzzy integral equations. Other important topics covered are fuzzy input-output analysis, fuzzy mathematics of finance, fuzzy PERT (project evaluation and review technique). No previous knowledge of fuzzy sets is needed. The mathematical background is assumed to be elementary calculus.