Statistics is increasingly used in all sciences. The use of advanced and improved statistical programs on computers has facilitated its development. This book combines the basic theory of Statistics with examples, exercises, applications, and instructions for using statistical programs on computers (MINITAB, SPSS, as well as the well-known EXCEL spreadsheet). Its purpose is to present and explain the basic statistical concepts in a simple, understandable, and comprehensive way in the topics it covers. It also aims to help the reader use the appropriate statistical methods systematically in various research needs and to encourage the use of statistical programs for proper and complete analysis. For this purpose, in this 4th improved and enriched edition of the book, special emphasis has been given to the instructions for using the three programs (MINITAB, SPSS, EXCEL) in detail in each chapter. If after reading the book and learning the covered topics, we are able to know what we are applying, where, and how, then the book has achieved its purpose.