Statistics Without Tears / Derek Rownt → Обява 23978485

Statistics Without Tears / Derek Rownt

Contents

Introduction 9

How to use this book 10

1. Statistical inquiry 13

Making sense of experience 14 What is statistics? 17 Descriptive and inferential statistics 19

Collecting a sample 23

2. Describing our sample 28

Statistical variables 28

Error, accuracy and approximations 35

3. Summarizing our data 38

Tables and diagrams 38 Central tendency (averages) 48

Measures of dispersion 50

4. The shape of a distribution 57

Skewed distributions 58 Introducing the normal distribution 64

Proportions under the normal curve 72

Comparing values 79

5. From sample to population 82

Estimates and inferences 82 The logic of sampling 86

A distribution of sample-means 87

Estimating the population-mean 94

Estimating other parameters 99

6. Comparing samples 102

From

the same or different populations? 102 Significance testing 107 The

significance of significance 116 Comparing dispersions 122

Non-parametric methods 124

7. Further matters of significance 128

One- versus two-tailed tests 129 z-tests and t-tests 139

Comparing several means 141 Comparing proportions 150

8. Analysing relationships 155

Paired values 156

Three kinds of correlation 160

The strength of a correlation 161

The significance of a correlation coefficient 164

Interpreting a correlation coefficient 169

Prediction and regression 176

Postscript 185

Review 186 Caution 188

Bibliography 191

Index 197

***

Acknowledgements

This

book is dedicated to Professor Peter Moore of the London Business

School who gave me just the kind of confidence in approaching statistics

that I hope my book will give to its readers.

I take this

opportunity also of thanking my Open University colleagues, Professor

Brian Lewis, John Bibby, Gordon Burt and Fred Lockwood - and Penguin’s

advisory editor, David Nelson -for their detailed and constructive

comments on earlier drafts which helped me greatly in preparing this

final version of the book. Lastly, I thank my secretary, Heida Darling,

for producing the immaculate typescript on which those comments were

made.

***

WHAT ARE STATISTICS? HOW DO YOU THINK STATISTICALLY?

This

book is written in the belief that the basic concepts of statistics can

be learnt without having to perform calculations. If you are about to

take a course in statistics, or if you want to know what the

statisticians are trying to say to you, then this is the book for you.

With it you can prime yourself with the ideas of the subject before

getting involved in the associated calculations.

Teaching by means of

words and diagrams rather than through figures, formulae and equations,

the author is providing an approach for the non-mathematical reader. To

prevent this process from being too one-sided Rowntree has included

questions in his argument; answer them as you go and you will be able to

tell how far you have mastered the subject.

This ‘tutorial in print’ is designed for everyone who needs or wants to know how statistics work.

Cover illustration by Michael Foreman

ISBN 0-14-022326-6

A PELICAN BOOK / Mathematics

9 780140 223262

***

PENGUIN BOOKS

Published by the Penguin Group 27 Wrights Lane, London W8 5TZ, England

Viking

Penguin Inc., 40 West 23rd Street, New York, New York 10010, USA

Penguin Books Australia Ltd, Ringwood, Victoria, Australia

Penguin

Books Canada Ltd, 2801 John Street, Markham, Ontario, Canada L3R 1B4

Penguin Books (NZ) Ltd, 182-190 Wairau Road, Auckland 10, New Zealand

Penguin Books Ltd, Registered Offices: Harmondsworth, Middlesex, England First published 1981

Reprinted 1981, 1983, 1984, 1985, 1987 (twice)

Copyright © Derek Rowntree, 1981 All rights reserved

Printed and bound in Great Britain by Cox & Wyman Ltd, Reading Set in Monotype Times

Except

in the United States of America, this book is sold subject to the

condition that it shall not, by way of trade or otherwise, be lent,

re-sold, hired out, or otherwise circulated without the publisher’s

prior consent in any form of binding or cover other than that in which

it is published and without a similar condition including this condition

being imposed on the subsequent purchaser

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