Statistics: Principles and Methods, 7th Edition

1

Introduction to Statistics

1 The Subject and Scope of Statistics

2 Statistics in Aid of Scientific Inquiry

3 Two Basic Concepts—Population and Sample

4 The Purposeful Collection of Data

5 Objectives of Statistics

Hometown fans attending today's game are but a sample of the population of all local football fans. A self-selected sample may not be entirely representative of the population on issues such as ticket price increases.

Surveys Provide Information About the Population

What is your favorite spectator sport?

Football	40.5%
Baseball	14.0%
Basketball	10.8%
Other	34.7%

College and professional sports are combined in our summary.¹ Clearly, football is the most popular spectator sport. Actually, the National Football League by itself is more popular than baseball.

For many years, baseball was most popular according to similar surveys. Surveys, repeated at different times, can detect trends in opinion.

1. THE SUBJECT AND SCOPE OF STATISTICS

Statistical reasoning allows us to learn from observations that exhibit considerable variation and to make good decisions in the presence of uncertainty. These are, of course, the conditions that dominate our modern world. To introduce this subject, we first develop a definition of statistics as a subject and then give examples that are typically encountered in our everyday lives.

1.1 WHAT IS STATISTICS?

Historically, the word ...