Our objective has been to write a text that would come into the statistics market between the two texts written by Paul G. Hoel (or the two texts written by John E. Freund). We have tried to cover most of the material in their mathematical statistics books, but we have used mathematics only slightly more difficult than that used in their elementary books. Calculus is used only in sections where the argument is difficult to develop without it; although this puts the calculus student at an advantage, we have made a special effort to design these sections so that a student without calculus can also follow.
By requiring a little more mathematics than many other elementary texts we have been able to treat many important topics normally covered only by books in mathematical statistics: for example, the relation of sampling and inference to the theory of probability and random variables. Another objective has been to show the logical relation between topics that have often appeared in texts as separate and isolated chapters: for example, the equiv¬alence of interval estimation and hypothesis testing, of the (test and F test, and of analysis of variance and regression using dummy variables. In every case our motivation has been twofold: to help the student appreciate-indeed enjoy-the underlying logic, and to help him arrive at answers to practical problems. .

We wrote the first edition of Understanding Statistics with our late colleague Dr. Arnold Naiman for students with little mathematical background, such as those we had all worked with at Nassau Community College for a number of years. We wanted a text that would be elementary enough to reach these students and still be mathematically sound and suitable for a one-semester college-level course. We are pleased that the text has "worked" for so many people. Over a period of 10 years, through two editions, many students and professors who have used the book have given us their comments on it. We have learned from them that its major strengths are its readability, its often humorous approach, and its problem sets. In putting together this third edition, we have tried to maintain these strengths while responding to users who have recommended changes.

The objective of this book is to show readers how statistics is used, not to train them to be statisticians. Students using it will gain an appreciation of the proper use of statistics, and statistical terms that confront them in textbooks, newspapers, magazines, and on TV and radio. Our major emphasis is on understanding sampling and hypothesis testing.

In this edition we have included a class survey at the beginning of the book so that students will have real data about themselves to use. We then pose problems based on these data in special sets of questions at the end of most exercise sets. We have found this option particularly useful during the early part of the course.