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Chapter 6: Descriptive Statistics – Univariate Analysis

Introduction

Generating Descriptive Statistics for Continuous Variables

Investigating the Distribution of Horsepower

Adding a Classification Variable in the Summary Statistics Tab

Computing Frequencies for Categorical Variables

Creating a Filter Within a Task

Creating a Box Plot

Conclusion

Chapter 6 Exercises

Introduction

Before you begin any statistical test, you should spend some time “getting to know your data.” This chapter describes ways to examine both continuous and categorical data using a variety of techniques, including descriptive statistical measures such as means and standard deviations as well as graphical techniques such as histograms and box plots. The term univariate describes single variables and not the relationship between variables, which is a topic discussed in several of the later chapters in this book (such as correlation and regression).

This step is so important because understanding your data is necessary when you are choosing appropriate statistical tests to perform. Also, describing your data, especially using graphical techniques, is one way to spot possible errors in your data.

Generating Descriptive Statistics for Continuous Variables

Let’s use the CARS data set, which is located in the SASHELP library, to demonstrate how to produce descriptive statistics for continuous and categorical variables. Start by selecting Summary Statistics from the Statistics tab on the Tasks and Utilities  Tasks menu, as shown in Figures 6.1 and 6.2 below.

Figure 6.1: Selecting Summary Statistics from the Statistics Task Menu


Double-click this selection to bring up the following screen.

Figure 6.2: DATA Tab for Summary Statistics


A Gentle Introduction to Statistics Using SAS Studio

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