The selection of topics in this book is traditional for courses in probability theory and mathematical statistics. These are joint probability distributions and moments of random variables, hypothesis testing, estimates of distribution parameters, confidence intervals. Study by samples, Markov chains, theory of statistical solutions are also considered. A significant number of examples of an applied nature are included, of which many are brought to the final numerical answers. These examples are not only intended to illustrate the theory, they are close to the tasks that graduates will be able to meet in future work. In this respect, the book is similar to the statistics textbooks used in Western universities. For undergraduate and graduate students specializing in economics, business informatics, computer science.