Book Image

Data Analysis Using SQL and Excel - Second Edition

By : Gordon S. S. Linoff
Book Image

Data Analysis Using SQL and Excel - Second Edition

By: Gordon S. S. Linoff

Overview of this book

Data Analysis Using SQL and Excel, 2nd Edition shows you how to leverage the two most popular tools for data query and analysis—SQL and Excel—to perform sophisticated data analysis without the need for complex and expensive data mining tools. Written by a leading expert on business data mining, this book shows you how to extract useful business information from relational databases. You'll learn the fundamental techniques before moving into the "where" and "why" of each analysis, and then learn how to design and perform these analyses using SQL and Excel. Examples include SQL and Excel code, and the appendix shows how non-standard constructs are implemented in other major databases, including Oracle and IBM DB2/UDB. The companion website includes datasets and Excel spreadsheets, and the book provides hints, warnings, and technical asides to help you every step of the way. Data Analysis Using SQL and Excel, 2nd Edition shows you how to perform a wide range of sophisticated analyses using these simple tools, sparing you the significant expense of proprietary data mining tools like SAS.
Table of Contents (18 chapters)
Free Chapter
1
Foreword
17
EULA

Counting Possibilities

Averages are interesting, but many of the comparisons between customers involve counts, such as the number of customers who have responded to an offer, or who have stopped, or who prefer particular products. Counting is a simple process, and one that computers excel at.

Counting is not just about individuals, it is also about counting combinations. For instance, if there are ten teams in a baseball league, how many different possible games are there? Figure 3.6

Points A-J as vertices of Decagon. Each vertex connected to nine other vertices. Lines intersect forming grid like structure.

Figure 3.6: There are 45 different possible games in a Little League club with ten teams. In this chart, each line connecting two boxes represents one possible game.

The study of such combinations is called combinatorics, a field that straddles probability and statistics. The rest of the chapter looks at statistical approximations to questions about combinations, approximations that are good enough for everyday use.

This section starts with a small example that can easily be illustrated and counted by...