Fundamentals of Statistics

Abstract

process you face. Interpretation also means knowing when to ignore results, either because they are misleading, are produced by incorrect methods, or just restate the obvious, as this news story " reported " by the comedian David Letterman illustrates: USA Today has come out with a new survey. Apparently, 3 out of every 4 people make up 75% of the population. As newer technologies allow people to process and analyze ever-increasing amounts of data, statistics plays an increasingly important part of many deci-sion-making processes today. Reading this chapter will help you understand the fundamentals of statistics and introduce you to concepts that are used throughout this book. The five words population, sample, parameter, statistic (singular), and variable form the basic vocabulary of statistics. You cannot learn much about statis-tics unless you first learn the meanings of these five words. Population CONCEPT All the members of a group about which you want to draw a con-clusion. EXAMPLES All U.S. citizens who are currently registered to vote, all patients treated at a particular hospital last year, the entire daily output of a cereal factory' s production line. Sample CONCEPT The part of the population selected for analysis. EXAMPLES The registered voters selected to participate in a recent survey concerning their intention to vote in the next election, the patients selected to fill out a patient-satisfaction questionnaire, 100 boxes of cereal selected from a factory' s production line. Parameter CONCEPT A numerical measure that describes a characteristic of a population. EXAMPLES The percentage of all registered voters who intend to vote in the next election, the percentage of all patients who are very satisfied with the care they received, the average weight of all the cereal boxes produced on a factory' s production line on a particular day. CHAPTER 1 FUNDAMENTALS OF STATISTICS 2 1.1 i m p o r ta n t p o i n t CH01 p.001-016 08.12.04 8:33 AM Page 2