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

Weighted Linear Regression

Bubble charts are a natural way to visualize many types of summarized data. The data is located on the chart according to X- and Y-values, and the size of each bubble is the frequency count. Alas, when Excel calculates the best-fit line in a bubble chart, it does not take into account the sizes of bubbles. The resulting best-fit line does a poor job showing trends in the data.

The way to solve this problem is by using weighted linear regression to take the sizes of the bubbles into account. Unfortunately, this capability is not built into Excel directly. There are two ways to do the calculation. One is to apply the formulas from the previous section, adjusting the various intermediate sums for the frequencies. The other uses special...