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 Contents: Introduction.- Fuzzy Sets.- Solving Fuzzy Equations.- Fuzzy Mathematics in Finance.- Fuzzy Non-Linear Regression.Operations Research.- Fuzzy Differential Equations.- Fuzzy Difference Equations.- Fuzzy Partial Differential Equations.- Fuzzy Eigenvalues.- Fuzzy Integral Equations.Summary and Conclusions.- Appendix: Evolutionary Algorithm