Chapter 1

Data, Statistics, and Decisions


check Introducing statistical concepts

check Generalizing from samples to populations

check Getting into probability

check Testing hypotheses

check Two types of error

Statistics? That’s all about crunching numbers into arcane-looking formulas, right? Not really. Statistics, first and foremost, is about decision-making. Some number-crunching is involved, of course, but the primary goal is to use numbers to make decisions. Statisticians look at data and wonder what the numbers are saying. What kinds of trends are in the data? What kinds of predictions are possible? What conclusions can we make?

To make sense of data and answer these questions, statisticians have developed a wide variety of analytical tools.

About the number-crunching part: If you had to do it via pencil-and-paper (or with the aid of a pocket calculator), you’d soon get discouraged with the amount of computation involved and the errors that might creep in. Software like R helps you crunch the ...

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