Statistics for Big Data For Dummies

Chapter 12

A Plot to Get Graphical: Graphical Techniques

In This Chapter

Delving into several graphical techniques you can use to analyze data

Comprehending the advantages and disadvantages of different plotting approaches

Determining how to choose the right graphical technique for any situation

You use graphs to gain insights into the statistical properties of a dataset. It’s often easy to see patterns or relationships in a dataset that would be easy to miss with numerical techniques, and this is especially true for large datasets.

This chapter introduces several of the most important graphical techniques for analyzing datasets:

• Stem-and-leaf plots
• Scatter plots
• Box plots
• Histograms
• Quantile-quantile (QQ) plots
• Autocorrelation plots

Stem-and-Leaf Plots

A stem-and-leaf plot is a graphical device in which the distribution of a dataset is organized by the numerical value of the observations in the dataset. The diagram consists of a “stem,” showing the different categories in the data, and a “leaf,” which shows the values of the individual observations in the dataset.

For example, the following is a stem-and-leaf diagram for the daily prices of Microsoft stock from January 1, ...