Chapter Introduction

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2

Frequency Distributions

LEARNING OBJECTIVES

  • Make a frequency distribution for a set of data.

  • Decide if a number is discrete or continuous.

  • Choose and make the appropriate graph for a frequency distribution.

  • Describe modality, skewness, and kurtosis for a frequency distribution.

  • Make a stem and leaf display.

CHAPTER OVERVIEW

The purpose of statistics is data reduction, taking a mass of numbers and reducing them in some way to bring order to them. Chapter 1 showed how organizing binge drinking rates for 18- to 25-year-olds in the United States—alphabetically or from low to high—made them easier to understand. That just involved reorganizing the data, not reducing it. Chapter 2 covers some data reduction techniques, making tables and graphs. It also introduces another way to think about numbers, whether the number is continuous or discrete, and talks about the “shapes” data can take.

2.1 Frequency Distributions

2.2 Discrete Numbers and Continuous Numbers

2.3 Graphing Frequency Distributions

2.4 Shapes of Frequency Distributions