Like the previous editions, this third edition of Introduction to Statistics has been written to serve as an introductory statistics text for students majoring in any of the academic disciplines, whether it be sociology, psychology, eco-nomics, business administration, or one of the sciences. A knowledge of high school algebra is sufficient to comprehend the basic concepts of descriptive and inferential statistics that are presented, although experience seems to in-dicate that a student benefits more from such a course when it is preceded by either a semester course in elementary functions or finite mathematics. In preparing this third edition, all examples and exercises dealing with numerical measurements have been converted to metric units. Unlike the first two editions in which the exercises were placed only at the end of each chapter, now the numerous illustrative exercises, many of which are new, have been placed immediately following appropriate sections within each chapter. Op-tional statistical concepts and procedures defined throughout many of the ex-ercise sets may be included at the discretion of the professor. A Student Study Guide, which provides additional insight and practice in solving the various types of problems presented throughout the text, accompanies this edition. The concepts of descriptive statistics, which previously were scattered throughout the text, have now been placed in the first three chapters. To complement this area, the treatment of percentiles, quartiles, and deciles has been expanded to cover both grouped and ungrouped data, the Pearsonian coefficient of skewness is defined, and new material has been added to illus-trate the use of a random number table in selecting a random sample. The field of modern statistics, with an increased emphasis on statistical inference.