Statistics Essentials For Dummies (2 page)
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Library of Congress Control Number: 2010925241
ISBN: 978-0-470-61839-4
Manufactured in the United States of America
10 9 8 7 6 5 4 3 2 1
About the Author
Deborah Rumsey
is a Statistics Education Specialist and Auxiliary Professor at The Ohio State University. Dr. Rumsey is a Fellow of the American Statistical Association and has won a Presidential Teaching Award from Kansas State University. She has served on the American Statistical Association's Statistics Education Executive Committee and the Advisory Committee on Teacher Enhancement, and is the editor of the Teaching Bits section of the
Journal of Statistics Education.
She is the author of the books
Statistics For Dummies, Statistics II For Dummies, Probability For Dummies,
and
Statistics Workbook For Dummies.
Her passions, besides teaching, include her family, fishing, bird watching, getting "seat time" on her Kubota tractor, and cheering the Ohio State Buckeyes to another national championship.
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Introduction
This book is designed to give you the essential, nitty-gritty information typically covered in a first semester statistics course. It's bottom-line information for you to use as a refresher, a resource, a quick reference, and/or a study guide. It helps you decipher and make important decisions about statistical polls, experiments, reports and headlines with confidence, being ever aware of the ways people can mislead you with statistics, and how to handle it.
Topics I work you through include graphs and charts, descriptive statistics, the binomial, normal, and
t-
distributions, two-way tables, simple linear regression, confidence intervals, hypothesis tests, surveys, experiments, and of course the most frustrating yet critical of all statistical topics: sampling distributions and the Central Limit Theorem.
About This Book
This book departs from traditional statistics texts and reference/supplement books and study guides in these ways:
Clear and concise step-by-step procedures
that intuitively explain how to work through statistics problems and remember the process.
empower you to know you're doing things right and whether others do it wrong.
so you can quickly zoom in on that concept or technique you need, without having to read other material first.
reinforce your understanding and help you immediately see how to apply the concepts in practical settings.
helps you remember and put into practice essential statistical concepts and techniques.
Conventions Used in This Book
I refer to statistics in two different ways: as numerical results (such as means and medians); or as a field of study (for example, "Statistics is all about data.").
The second convention refers to the word
data
. I'm going to go with the plural version of the word data in this book. For example "data are collected during the experiment" — not "data is collected during the experiment."
Foolish Assumptions
I assume you've had some (not necessarily a lot of) previous experience with statistics somewhere in your past. For example, you can recognize some of the basic statistics such as the mean, median, standard deviation, and perhaps correlation; you can handle some graphs; and you can remember having seen the normal distribution. If it's been a while and you are a bit rusty, that's okay; this book is just the thing to jog your memory.
If you have very limited or no prior experience with statistics, allow me to suggest my full-version book,
Statistics for Dummies
, to build up your foundational knowledge base. But if you are someone who has not seen these ideas before and either doesn't have time for the full version, or you like to plunge into details right away, this book can work for you.
I assume you've had a basic algebra background and can do some of the basic mathematical operations and understand some of the basic notation used in algebra like
x
,
y
, summation signs, taking the square root, squaring a number, and so on. (If you'd like some backup on the algebra part, I suggest you consider
Algebra I For Dummies
and
Algebra II For Dummies
(Wiley)).
Icons Used in This Book
Here are the road signs you'll encounter on your journey through this book:
Tips refer to helpful hints or shortcuts you can use to save time.
Read these to get the inside track on why a certain concept is important, what its impact will be on the results, and highlights to keep on your radar.
These alert you to common errors that can cause problems, so you can steer around them.
This book is written in a nonlinear way, so you can start anywhere and still be able to understand what's happening. However, I can make some recommendations for those who are interested in knowing where to start.
For a quick overview of the topics to refresh your memory, check out Chapter 1. For basic number crunching and graphs, see Chapters 2 and 3. If you're most interested in common distributions, see Chapters 4 (binomial); 5 (normal); and 9 (
t
-distribution). Confidence intervals and hypothesis testing are found in Chapters 7 and 8. Correlation and regression are found in Ch 10, and two-way tables and independence are tackled in Ch 11. If you are interested in evaluating and making sense of the results of medical studies, polls, surveys, and experiments, you'll find all the info in Chapters 12 and 13. Common mistakes to avoid or watch for are seen in Chapter 14.
