This textbook systematically presents fundamental methods of statistical analysis: from probability and statistical distributions, through basic concepts of statistical inference, to a collection of methods of analysis useful for scientific research. It is rich in tables, diagrams, and examples, in addition to theoretical justification of the methods of analysis introduced. Each chapter has a section entitled "Exercises and Problems" to accompany the text. There are altogether about 300 exercises and problems, answers to the selected problems are given. A section entitled "Proof of the Results in This Chapter" in each chapter provides interested readers with material for further study.