Table of Contents
Part 1 The Basics 1
1 Let's Get Started 3
What Is Statistics and Why Do You Need It? 4
Types of Statistics 5
Descriptive Statistics-the Minor League 5
Inferential Statistics-the Major League 6
Population vs. Sample 7
Parameter vs. Statistic 8
Ethics and Statistics-It's a Dangerous World Out There 9
Practice Problems 12
2 Data, Data Everywhere and Not a Drop to Drink 13
The Importance of Data 14
The Sources of Data-Where Does All This Stuff Come From? 15
Direct Observation-I'll Be Watching You 16
Experiments-Who's in Control? 16
Surveys-Is That Your Final Answer? 16
Data and Types of Variables 17
Quantitative vs. Qualitative Variables 17
Discrete vs. Continuous Variables 17
Dependent vs. Independent Variables 18
Types of Measurement Scales-a Weighty Topic 18
Nominal Level of Measurement 18
Ordinal Level of Measurement 19
Interval Level of Measurement 19
Ratio Level of Measurement 19
Computers to the Rescue 20
The Role of Computers in Statistics 21
Installing the Data Analysis Add-In 21
Practice Problems 24
3 Displaying Descriptive Statistics 27
Frequency Distributions 28
The Frequency Distribution 29
(A Distant) Relative Frequency Distribution 30
The Cumulative Frequency Distribution 31
The Contingency Table 32
Charting Your Course: Graphs 33
Histogram 33
Letting Excel Do Our Dirty Work 34
Bar Chart 38
Pie Chan 41
Line Chart 45
The Stem and Leaf Display-Statistical Flower Power 46
Practice Problems 48
4 Calculating Descriptive Statistics: Measures of Central Tendency (Mean, Median, and Mode) 49
Measures of Central Tendency 50
Mean 50
Median 52
Mode 53
Weighted Mean 53
Measures of Central Tendency for Grouped Data: 55
How Does One Choose? 57
Using Excel to Calculate Central Tendency 57
Practice Problems 60
5 Calculating Descriptive Statistics: Measures of Dispersion 63
Measures of Dispersion for Ungrouped Data 64
Range 64
Variance 65
Using the Raw Score Method (When Grilling) 66
Variance of a Population 67
Standard Deviation 68
Measures of Dispersion for Grouped Data 69
Measures of Relative Position 70
Quartiles 70
Interquartile Range (IQR) 72
Excel to the Rescue 73
Practice Problems 74
Part 2 Probability Topics 77
6 Introduction to Probability 79
What is Probability? 80
Classical Probability 80
Empirical Probability 81
Subjective Probability 83
Relationship Between Events 83
Mutually Exclusive Events 83
Independent Events 84
Complementary Events 84
Union and intersection of Events 85
The Union of Events: A Marriage Made in Heaven 85
The Intersection of Events 85
Practice Problems 86
7 Probability and Counting Rules 89
Addition Rule of Probabilities 90
Conditional Probability 91
Multiplication Rule of Probabilities 93
Bayes' Theorem 94
Counting Principles 95
The Fundamental Counting Rule 95
Permutations 98
Combinations 99
Using Excel to Calculate Factorials, Permutations, and Combinations 100
Practice Problems 102
8 Probability Distributions 105
Basic Concepts of Probability Distributions 106
Random Variables 106
Probability Distributions 106
Rules for Discrete Probability Distributions 108
The Mean of Discrete Probability Distributions 109
The Variance and Standard Deviation of Discrete Probability Distributions 110
Practice Problems 111
9 The Binomial Probability Distribution 113
Characteristics of a Binomial Experiment 114
The Binomial Probability Distribution 115
Binomial Probability Tables 117
Using Excel to Calculate Binomial Probabilities 118
The Mean and Standard Deviation for the Binomial Distribution 120
Practice Problems 121
10 The Poisson Probability Distribution 123
Characteristics of a Poisson Process 124
The Poisson Probability Distribution 125
Poisson Probability Tables 127
Using Excel to Calculate Poisson Probabilities 130
Using the Poisson Distribution as an Approximation to the Binomial Distribution 132
Practice Problems 133
11 The Normal Probability Distribution 135
Characteristics of the Normal Probability Distribution 136
Calculating Probabilities for the Normal Distribution 138
Calculating Probability Using the Z-Score 139
Using the Standard Normal Table 141
The Area Under the Normal Distribution and the Empirical Rule 146
Calculating formal Probabilities Using Excel 147
Using the Normal Distribution as an Approximation to the Binomial Distribution 148
Practice Problems 151
Part 3 Inferential Statistics 153
12 Sampling 155
Why Sample? 156
Random Sampling 157
Simple Random Sampling 157
Systematic Sampling 160
Cluster Sampling 162
Stratified Sampling 162
Sampling Error and Sampling Bias 163
Sampling Error 163
Sampling Bias 164
Examples of Poor Sampling Techniques 164
Practice Problems 165
13 Sampling Distributions 167
What Is a Sampling Distribution? 168
Sampling Distribution of the Sample Means 168
Mean of the Sampling Distribution of the Sample Means 171
Standard Error of the Sampling Distribution of the Sample Means 173
The Central Limit Theorem 175
Putting the Central Limit Theorem to Work 177
Sampling Distribution of the Proportion 178
Calculating the Sample Proportion 179
Calculating the Standard Error of the Proportion 180
Practice Problems 181
14 Confidence Intervals 183
The Basics of Confidence Intervals 184
Point Estimate and Interval Estimate 184
The Principle of Confidence Intervals 185
The Probability of an Error (the Alpha Value) 185
Confidence Intervals for the Population Mean 186
When the Population Standard Deviation Is Known 186
Beware of Interpretation of the Confidence Interval! 188
The Effect of Changing Confidence Levels 190
The Effect of Changing the Sample Size 190
When the Population Standard Deviation Is Unknown 191
When the Population Standard Deviation Is Unknown and with Small Samples 192
Determining Sample She for the Population Mean 195
Using Excels Confidence Function 196
Confidence Intervals for the Population Proportion with Large Samples 198
Calculating the Confidence Interval for the Population Proportion 199
Determining Sample Size for the Proportion 200
Practice Problems 201
15 Hypothesis Testing with One Population 203
Hypothesis Testing: The Traditional Method 204
Procedures far Hypothesis Testing 204
1 The Null and Alternative Hypotheses 205
2 The Level of Significance 206
3 The Test Statistic 207
4 The Critical Value 207
5 State Your Decision 209
One-Tail vs. Two-Tail Tests 209
Two-Tail Hypothesis Testing 210
One-Tail Hypothesis Testing 211
Hypothesis Testing for the Population Mean 213
When Sigma Is Known 213
When Sigma Is Unknown and Using a Large Sample 214
When Sigma Is Unknown and Using a Small Sample 216
The Role of Alpha in Hypothesis Testing 219
The p-Value Method 220
The p-Value for a One-Tail Test 221
The p-Value for a Two-Tail Test 222
Using Excel for Hypothesis Testing 223
Using Excel's Norm.S.Dist Function 224
Using Excel's TDTST, T.DIST.RT, and T.DIST.2T Functions 225
Using Excels T.INV and T.INV.2T Functions 226
Hypothesis Testing for the Population Proportion with Large Samples 228
One-Tail Hypothesis Test for the Proportion 228
Two-Tail Hypothesis Test for the Proportion 230
Practice Problems 231
16 Hypothesis Testing with Two Populations 235
The Concept of Testing Two Populations 236
Sampling Distribution for the Difference in Means 236
Testing for the Differences Between Two Population Means with Independent Samples 238
When the Population Standard Deviations Are Known 238
Testing a Difference Other Than Zero 240
When the Population Standard Deviations Are Unknown 242
Unequal Population Variances When the Population Standard Deviations Are Unknown 242
Equal Population Variances When the Population Standard Deviations Are Unknown 245
To Pool or Not to Pool? 248
Testing for Differences Between Means with Dependent Samples 248
Letting Excel Do the Grunt Work 251
Testing for Differences Between Proportions with Independent Samples 256
Practice Problems 259
Appendixes
A Solutions to "Practice Problems" 263
B Statistical Tables 281
C Glossary 291
D Statistics Reference Glossary 299
E Excel Reference Glossary 303
Index 305
