Introduction to Statistics - Saint Paul Public Schools

1 Introductionto Statistics and Data AnalysisThis page intentionally left blank Introductionto Statistics and Data AnalysisThird EditionRoxy PeckCalifornia Polytechnic State University, San Luis ObispoChris OlsenGeorge Washington High School, Cedar Rapids, IAJay DevoreCalifornia Polytechnic State University, San Luis ObispoAustralia Brazil Canada Mexico Singapore Spain United Kingdom United StatesIntroduction to Statistics and Data Analysis,Third EditionRoxy Peck, Chris Olsen, Jay DevoreAcquisitions Editor: Carolyn CrockettDevelopment Editor: Danielle DerbentiAssistant Editor: Beth GershmanEditorial Assistant: Ashley SummersTechnology Project Manager: Colin BlakeMarketing Manager: Joe RogoveMarketing Assistant: Jennifer LiangMarketing Communications Manager: Jessica PerryProject Manager, Editorial Production: Jennifer RisdenCreative Director: Rob HugelArt Director: Vernon BoesPrint Buyer: Karen HuntPermissions Editor: Isabel AlvesProduction Service: Newgen AustinText Designer: Stuart PatersonPhoto Researcher: Gretchen MillerCopy Editor: Nancy DicksonIllustrator: Jade Myers.

2 Newgen IndiaCover Designer: Stuart PatersonCover Image: paul Chesley/Getty ImagesCover Printer: Courier Corporation/KendallvilleCompositor: Newgen IndiaPrinter: Courier Corporation/Kendallville 2008, 2005 Duxbury, an imprint of Thomson Brooks/Cole, apart of The Thomson Corporation. Thomson, the Star logo, andBrooks/Cole are trademarks used herein under RIGHTS RESERVED. No part of this work covered by thecopyright hereon may be reproduced or used in any form or byany means graphic, electronic, or mechanical, including photo-copying, recording, taping, Web distribution, information storageand retrieval systems, or in any other manner without the writ-ten permission of the in the United States of America1 2 3 4 5 6 7 11 10 09 08 07 ExamView and ExamView Pro are registered trademarks of FSCreations, Inc.

3 Windows is a registered trademark of theMicrosoft Corporation used herein under license. Macintosh andPower Macintosh are registered trademarks of Apple Computer,Inc. Used herein under of Congress Control Number: 2006933904 Student Edition:ISBN-13: 978-0-495-11873-2 ISBN-10: 0-495-11873-7 Thomson Higher Education10 Davis DriveBelmont, CA 94002-3098 USAFor more information about our products, contact us at:Thomson Learning Academic Resource Center1-800-423-0563 For permission to use material from this text or product, submit arequest online at additional questions about permissions can be submitted bye-mail to To my nephews, Jesse and Luke Smidt, who bet I wouldn t put their names in this P.

4 To my wife, Sally, and my daughter, AnnaC. O. To Carol, Allie, and PECK is Associate Dean of theCollege of Science and Mathematicsand Professor of Statistics at CaliforniaPolytechnic State University, San LuisObispo. Roxy has been on the facultyat Cal Poly since 1979, serving for sixyears as Chair of the Statistics Department beforebecoming Associate Dean. She received an inMathematics and a in Applied Statistics fromthe University of California, Riverside. Roxy is na-tionally known in the area of Statistics education,and in 2003 she received the American StatisticalAssociation s Founder s Award, recognizing her con-tributions to K 12 and undergraduate Statistics edu-cation.

5 She is a Fellow of the American StatisticalAssociation and an elected member of the Interna-tional Statistics Institute. Roxy has recently com-pleted five years as the Chief Reader for the Ad-vanced Placement Statistics Exam and currentlychairs the American Statistical Association s JointCommittee with the National Council of Teachers ofMathematics on Curriculum in Statistics and Proba-bility for Grades K 12. In addition to her texts in in-troductory Statistics , Roxy is also co-editor ofStatisti-cal Case Studies: A Collaboration Between Academeand Industryand a member of the editorial board forStatistics: A Guide to the Unknown, 4th edition.

6 Out-side the classroom and the office, Roxy likes to traveland spends her spare time reading mystery also collects Navajo rugs and heads to New Mex-ico whenever she can find the OLSEN has taught Statistics at George Washington High School inCedar Rapids, Iowa, for over 25 is a past member of the Ad-vanced Placement Statistics Test De-velopment Committee and the authorof the Teacher s Guide for Advanced Placement Sta-tistics. He has been a table leader at the AP Statisticsreading for 6 years and since the summer of 1996 hasbeen a consultant to the College Board.

7 Chris leadsworkshops and institutes for AP Statistics teachersin the United States and internationally. Chris wasthe Iowa recipient of the Presidential Award for Ex-cellence in Science and Mathematics Teaching in1986. He was a regional winner of the IBM Com-puter Teacher of the Year award in 1988 and receivedthe Siemens Award for Advanced Placement in math-ematics in 1999. Chris is a frequent contributor tothe AP Statistics Electronic Discussion Group andhas reviewed materials for The Mathematics Teacher,the AP Central web site, The American Statistician,and the Journal of the American Statistical Associa-tion.

8 He currently writes a column for Statsmaga-zine. Chris graduated from Iowa State Universitywith a major in mathematics and, while acquiringgraduate degrees at the University of Iowa, concen-trated on Statistics , computer programming, psycho-metrics, and test development. Currently, he divideshis duties between teaching and evaluation; in addi-tion to teaching, he is the assessment facilitator forthe Cedar Rapids, Iowa, Community Schools . In hisspare time he enjoys reading and hiking. He and hiswife have a daughter, Anna, who is a graduate stu-dent in Civil Engineering at Cal DEVORE earned his under-graduate degree in Engineering Sci-ence from the University of Californiaat Berkeley, spent a year at the Univer-sity of Sheffield in England, and fin-ished his in Statistics at StanfordUniversity.

9 He previously taught at the University ofFlorida and at Oberlin College and has had visitingappointments at Stanford, Harvard, the Universityof Washington, and New York University. From 1998to 2006, Jay served as Chair of the Statistics Depart-ment at California Polytechnic State University, SanLuis Obispo. The Statistics Department at Cal Polyhas an international reputation for activities in sta-tistics education. In addition to this book, Jay haswritten several widely used engineering statisticstexts and is currently working on a book in appliedmathematical Statistics .

10 He is the recipient of a dis-tinguished teaching award from Cal Poly and is aFellow of the American Statistical Association. Inhis spare time, he enjoys reading, cooking and eatinggood food, tennis, and travel to faraway places. He isespecially proud of his wife, Carol, a retired elemen-tary school teacher, his daughter Allison, who worksfor the Center for Women and Excellence in Boston,and his daughter Teri, who is finishing a graduateprogram in education at NYU. About the AuthorsviiContents1 The Role of Statistics and the Data Analysis Reasons to Study Nature and Role of and the Data Analysis of Data and Some Simple Graphical Displays12 Activity Sizes: Understanding Variability22 Activity Sizes23 Activity Meaningful Paragraph242 Collecting Data Studies: Observation and Comparative on Experimental on Observational Studies.