Matthew A. Barsalou 
ASQ Pocket Guide to Statistics for Six Sigma Black Belts [PDF ebook] 

Six Sigma Black Belts are expected to have the skills of a good experimenter, possessing both a deep understanding of statistics and a knowledge of the industry in which they work. This book is written for the Six Sigma Black Belt who needs an understanding of many statistical methods but does not use all of these methods every day. It is intended to be used as a quick reference, providing basic details and formulas. The methods presented here are laid out according to the Six Sigma DMAIC (Define, Measure, Analyze, Improve, Control) phases in which they are typically used. Included in appendices are a flowchart that provides the correct statistical test for a given use and type; flowcharts depicting the five steps for hypothesis testing; the statistical formulas in tables to serve as a quick reference; and statistical tables.