The Basic Practice of Statistics
SEVENTH EDITION
The Basic Practice
of Statistics
DAVID S. MOORE • WILLIAM I. NOTZ • MICHAEL A. FLIGNER
Purdue University
The Ohio State University University of California at Santa Cruz
Terri Ward
Karen Carson
Cara LeClair
Leslie Lahr and Jorge Amaral
Marie Dripchak
Laura Judge
Catriona Kaplan
Liam Ferguson
Victoria Garvey
Bailey James
Cecilia Varas
Eileen Liang
Vicki Tomaselli
Lisa Kinne
Denise Showers, Aptara®, Inc.
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Cover Credit:
© SoberP/istockphoto
Library of Congress Control Number: 2014950586
Student Edition Hardcover (packaged with EESEE/CrunchIt! access card):
ISBN-13: 978-1-4641-4253-6
ISBN-10: 1-4641-4253-X
Student Edition Loose-leaf (packaged with EESEE/CrunchIt! access card):
ISBN-13: 978-1-4641-7990-7
ISBN-10: 1-4641-7990-5
Instructor Complimentary Copy:
ISBN-13: 978-1-4641-7988-4
ISBN-10: 1-4641-7988-3
© 2015, 2013, 2010, 2007 by W. H. Freeman and Company
All rights reserved
Printed in the United States of America
First printing
W. H. Freeman and Company
41 Madison Avenue
New York, NY 10010
Houndmills, Basingstoke RG21 6XS, England
www.whfreeman.com
BRIEF CONTENTS
CHAPTER 0 Getting Started
PART I
EXPLORING DATA
Exploring Data: Variables and Distributions
CHAPTER 1 Picturing Distributions with Graphs
CHAPTER 2 Describing Distributions with Numbers
CHAPTER 3 The Normal Distributions
Exploring Data: Relationships
CHAPTER 4 Scatterplots and Correlation
CHAPTER 5 Regression
CHAPTER 6 Two-Way Tables*
CHAPTER 7 Exploring Data: Part I Review
PRODUCING DATA
PART II
CHAPTER 8 Producing Data: Sampling
CHAPTER 9 Producing Data: Experiments
CHAPTER 10 Data Ethics*
CHAPTER 11 Producing Data: Part II Review
PART III
FROM DATA PRODUCTION
TO INFERENCE
CHAPTER 12 Introducing Probability
CHAPTER 13 General Rules of Probability*
CHAPTER 14 Binomial Distributions*
CHAPTER 15 Sampling Distributions
CHAPTER 16 Confi dence Intervals: The Basics
1
11
13
47
75
101
127
163
179
201
203
227
253
267
275
277
303
327
345
373
*Starred material is not required for later parts of the text.
v
vi
BRIEF CONTENTS
CHAPTER 17 Tests of Signifi cance: The Basics
CHAPTER 18 Inference in Practice
CHAPTER 19 From Data Production to Inference:
Part III Review
391
415
439
PART IV
INFERENCE ABOUT VARIABLES
453
Quantitative Response Variable
CHAPTER 20 Inference about a Population Mean
CHAPTER 21 Comparing Two Means
Categorical Response Variable
CHAPTER 22 Inference about a Population Proportion
CHAPTER 23 Comparing Two Proportions
CHAPTER 24 Inference about Variables: Part IV Review
PART V
INFERENCE ABOUT
RELATIONSHIPS
CHAPTER 25 Two Categorical Variables:
The Chi-Square Test
CHAPTER 26 Inference for Regression
CHAPTER 27 One-Way Analysis of Variance:
Comparing Several Means
PART VI
OPTIONAL COMPANION CHAPTERS
(AVAILABLE ONLINE)
CHAPTER 28 Nonparametric Tests
CHAPTER 29 Multiple Regression
CHAPTER 30 More about Analysis of Variance
CHAPTER 31 Statistical Process Control
453
485
517
539
559
575
577
609
645
28-1
29-1
30-1
31-1
CONTENTS
To the Instructor: About This Book xi
Acknowledgments xx
Media and Supplements xxii
About the Authors xxv
CHAPTER 0 Getting Started 1
0.1 Where the data comes from matters 2
0.2 Always look at the data 3
0.3 Variation is everywhere 5
0.4 What lies ahead in this book 7
PART I
EXPLORING DATA 11
CHAPTER 1 Picturing Distributions with
Graphs 13
1.1 Individuals and variables 13
1.2 Categorical variables: pie charts and bar
graphs 16
1.3 Quantitative variables: histograms 21
1.4 Interpreting histograms 24
1.5 Quantitative variables: stemplots 29
1.6 Time plots 32
CHAPTER 2 Describing Distributions with
Numbers 47
2.1 Measuring center: the mean 48
2.2 Measuring center: the median 49
2.3 Comparing the mean and the median 50
2.4 Measuring variability: the quartiles 51
2.5 The fi ve-number summary and boxplots 53
2.6 Spotting suspected outliers and modifi ed
boxplots* 55
2.7 Measuring variability: the standard deviation 57
2.8 Choosing measures of center and variability 59
2.9 Using technology 61
2.10 Organizing a statistical problem 63
CHAPTER 3 The Normal Distributions 75
3.1 Density curves 75
3.2 Describing density curves 78
3.3 Normal distributions 80
*Starred material is not required for later parts of the text.
3.4 The 68–95–99.7 rule 82
3.5 The standard Normal distribution 85
3.6 Finding Normal proportions 86
3.7 Using the standard Normal table 88
3.8 Finding a value given a proportion 91
CHAPTER 4 Scatterplots and Correlation 101
4.1 Explanatory and response variables 101
4.2 Displaying relationships: scatterplots 103
4.3 Interpreting scatterplots 105
4.4 Adding categorical variables to scatterplots 109
4.5 Measuring linear association: correlation 111
4.6 Facts about correlation 113
CHAPTER 5 Regression 127
5.1 Regression lines 127
5.2 The least-squares regression line 131
5.3 Using technology 132
5.4 Facts about least-squares regression 135
5.5 Residuals 138
5.6 Infl uential observations 143
5.7 Cautions about correlation and regression 146
5.8 Association does not imply causation 148
CHAPTER 6 Two-Way Tables* 163
6.1 Marginal distributions 164
6.2 Conditional distributions 166
6.3 Simpson’s paradox 171
CHAPTER 7 Exploring Data: Part I Review 179
Part I Summary 181
Test Yourself 183
Supplementary Exercises 195
PART II
PRODUCING DATA 201
CHAPTER 8 Producing Data: Sampling 203
8.1 Population versus sample 204
8.2 How to sample badly 206
vii