ABSTRACT
An event is the simplest random phenomenon. Two dots appearing on the top face of a die, material or device failure, human error (such as, e.g., misinterpretation of the obtained signal) and/or his/her inability to successfully cope with an elevated mental workload (MWL), safe landing, unacceptable level of the leakage current in an electronic or optical device, and buckling of a compressed structural element, are all examples of events. The content of the applied probability theory is, in effect, a collection of different ways, methods, and approaches that enable one to evaluate the probabilities of occurrence of complex events from the known or anticipated probabilities of simple events. An outer space mission mishap is likely to happen if at least one of the three navigators makes an error. A random variable is a variable, which, as a result of an experiment with an unpredictable outcome, assumes a certain value that is unknown prior to the experiment.
