iii

PART I Producing Data 1

1 Where Do Data Come From? 3

2 Samples, Good and Bad 21

3 What Do Samples Tell Us? 39

4 Sample Surveys in the Real World 63

5 Experiments, Good and Bad 93

6 Experiments in the Real World 117

7 Data Ethics 141

8 Measuring 163

9 Do the Numbers Make Sense? 187

Part I Review 203

PART II Organizing Data 213

10 Graphs, Good and Bad 215

11 Displaying Distributions with Graphs 243

12 Describing Distributions with Numbers 267

13 Normal Distributions 293

14 Describing Relationships: Scatterplots and Correlation 315

15 Describing Relationships: Regression, Prediction, and Causation 339

16 The Consumer Price Index and Government Statistics 367

Part II Review 389

PART III Chance 403

17 Thinking about Chance 405

18 Probability Models 427

19 Simulation 445

20 The House Edge: Expected Values 465

Part III Review 481

PART IV Inference 491

21 What Is a Confidence Interval? 493

22 What Is a Test of Significance? 521

23 Use and Abuse of Statistical Inference 547

24 Two-Way Tables and the Chi-Square Test^* 571

Part IV Review 595