The exponential distribution is one of the most important probability distributions in the theory and application of statistics. Despite its importance, however, most texts devote too little attention to it and specialized handbooks include too many mathematical details. In a straightforward and engaging manner, this handbook thoroughly examines the exponential, Gamma, Weibull, and Pareto distributions. It provides a comprehensive study of various estimation and testing methods and features numerous applications drawn from biology, engineering, and sociological studies including real data sets, numerical examples, figures and tables.