# SurfStat contents

## SUMMARISING AND PRESENTING DATA

• TYPES OF VARIABLE
• 1-1-1.html
• Qualitative Data
• Quantitative Data
• Table - Hypothetical Data
Progress check
Exercises

• PRESENTING DISCRETE DATA
• 1-1-2.html
• Frequency Distributions
• Bar charts and Pareto charts
Progress check

• PRESENTING CONTINUOUS DATA
• 1-1-3.html
• Commodore Data
• Histograms
Example - Commodore prices
• In MINITAB the command is
• Java applet "Histogram"
• Dotplots
Example - The Commodore price data
Related topics
Progress check

• CHARACTERISTICS OF A DISTRIBUTION
• 1-2-1.html
• Modality and Symmetry
An example of positive skewness
(skew to the right)
An example of negative skewness
(skew to the left)
Progress check

• MEASURES OF CENTRAL TENDENCY ("Averages")
• 1-2-2.html
• Median
• Mode
• Notation
• Mean
• The MINITAB command for mean
• Comparison of Mean and Median
APPLET "Centres"
• Mean for Grouped Data
Example - Survey of 20 students in a STAT101 tutorial
Progress check

• MEASURES OF VARIABILITY
• 1-2-3.html
• Range
• Quartiles
• Procedure
• Interquartile Range
• Percentiles
Progress check

• 1-2-4.html
• Standard Deviation and Variance
Example - Data set A
Progress check

• 1-2-5.html
• Comments
• Boxplots
• The MINITAB command
• Five-number summary
Progress check

• NORMAL DISTRIBUTIONS
• 1-3-1.html
Example - Distribution of blood pressure
• Quincunx
Progress check

• 1-3-2.html
• Modelling
• Density Function
• Note:
• Relative Frequency
• Standard Normal Distribution
Progress check

• 1-3-3.html
Example: z < 1.05
Example: z > 1.05
Example: -1.05 <= z <= 1.05
• Exercise
Example - X ~ N(4, 9), X < 5
Example - Soft drink bottle filler
Progress check

• PRESENTING DATA FOR TWO CONTINUOUS MEASUREMENTS
• 1-4-1.html
• Introduction
• Scatterplots
Scatterplot of Income versus Age
Scatterplot of Income versus Age Classified by Sex
Example - Heights and weights of 6 female STAT101 students
Progress check

• 1-4-2.html
• Correlation
• Positive and Negative Association
• Linear Versus Nonlinear Association
• Correlation Coefficient
Example - Calculation of r for students' heights and weights
Progress check

• 1-4-3.html
• Properties of the correlation coefficient
• Interpretation of correlation
Progress check

• 1-4-4.html
• Regression
Example - Effects of storage conditions on shelf life
• Java applet "Regression"
• Method of Least Squares
Progress check

• 1-4-5.html
Notes
Example - American female runners
Progress check

• 1-5-1.html
• Simple Methods for Time Series Analysis
Examples - UK softwood imports
• MINITAB TSPLOT command
• Moving Averages
• MINITAB Macros
• Comments
Progress check

• EXPLORING DATA IN TABLES
• 1-5-2.html
• Dot Chart
Example - Newcastle restaurant survey
• Contingency Tables
Example - Number of deaths in Australia (1989)
• The need to consider group size
Example - Infant deaths in 1989
• Rules for presentation of tables
Progress check

## PRODUCING DATA

• INTRODUCTION
• 2-1-1.html
Example - Public opinion polls
• Bias
• Randomisation
Example - Teenage driving safety
Example - Salary versus age
• Cross-Sectional versus Longitudinal Studies

• PRINCIPLES OF STUDY DESIGN
• 2-1-2.html
• Overview
• Design of experiments
• Randomisation, Replication and Blocking
Example - Mice in the lab
• Comparison Groups
Examples of Observational Studies
• Confounding
Example - Gender and discrimination at UCB
• Questionnaire Design
Progress check

• 2-1-3.html
• The Scientific Method
• Principles of Scientific Experimentation
Example - Salk polio vaccine trial
• Randomised, Controlled, Double-Blinded Trial
• Summary of Study Design
Progress check

## VARIATION AND PROBABILITY

• INTRODUCTION
• 3-1-1.html
• A concept of Probability
Example - 10 000 coin tosses
Example - 2 coin tosses
• DEFINITIONS

• 3-1-2.html
• Discrete probability distributions
• Complement
Example - Reducing companies' discriminatory hiring practices
• Discrete Probability Distribution
Example - 1 coin toss
Example - 1 fair die throw
Example - 3 coin tosses

• INDEPENDENCE AND TREE MODELS FOR CALCULATING PROBABILITIES
• 3-1-3.html
Example - Fruit in 2 districts
Example - 2 security guards and their pagers
Example - Boys and girls in a family of 3
Example - Gender in human populations

• CONDITIONAL PROBABILITY
• 3-1-4.html
Example - A family of 3 children
Example - Gender of employees
• Independence Revisited

• BAYES' THEOREM
• 3-1-5.html
Example - Cervical (or breast) cancer
• Summary For Probability Calculations

• RANDOM VARIABLES
• 3-2-1.html
• Probability Distribution of a Discrete r.v.

• DISCRETE DISTRIBUTIONS
• 3-2-2.html
• Discrete Random Variable
Example - Family of 3 children.
Example - Bernoulli trials
Example - 2 dice are thrown

• 3-2-3.html
• The Binomial distribution
Example - A football team plays 3 games
Example - A quality control inspection system

• EXPECTED VALUE AND VARIANCE OF A RANDOM VARIABLE
• 3-2-5.html
• Example - Decision Analysis in Oil exploration
• Expected Value of a Random Variable
• Variance of a Random Variable
Example - Gender in a class of 5
• Expected Value and Variance for a Function of Random Variables
Example - Estimated profit prediction
Example - Metal component manufacturing

• CONTINUOUS RANDOM VARIABLES
• 3-2-6.html
• Relative Frequency Histogram
• Probability Density Function
Example - Uniform Continuous Distribution
• Uniform continuous random number generation in MINITAB

• NORMAL DISTRIBUTION
• 3-2-7.html
• Standard Normal Distribution
Example - Within 1 standard deviation of the mean
Example - Soft drink bottle filler example revisited

• NORMAL APPROXIMATION TO THE BINOMIAL DISTRIBUTION
• 3-2-8.html
• Shape of the Binomial Distribution
• The Binomial and the Normal Distributions Compared
• The MINITAB MPLOT command
• Continuity Correction and Accuracy
• Java applet "Discrete"
Example - Gender in a particular faculty

## STATISTICAL INFERENCE

• POPULATIONS, SAMPLES, ESTIMATES AND REPEATED SAMPLING
• 4-1-1.html
• Definitions
• Bias
Example - Health survey conducted in the Hunter Region
Example - Heights of women, 25 - 29

• POINT ESTIMATION AND INTERVAL ESTIMATION

• RESULTS FROM PROBABILITY THEORY
• 4-1-3.html
• Law of Averages
• Law of Large Numbers
• Central Limit Theorem

• ONE CONTINUOUS VARIABLE
• 4-1-4.html
• Sampling Distribution of the Sample Mean
Properties of the Sampling Distribution

• 4-1-5.html
• Interpretation of Confidence Intervals
• Comments
• Hypothesis Testing
Example - Bolt production
• The First Approach
• Remarks
• The Second Approach
• Steps for hypothesis testing

• 4-1-6.html
• Interpretation of p-values
• The 5% level
• Comments
• Type I and Type II errors, and the power of a statistical test

• 4-1-7.html
Example - 300 mL bottles of softdrink
• Comments

• COMPARING MEANS OF TWO CONTINUOUS VARIABLES
• 4-2-1.html
• Introduction
Example - From the MINITAB handbook page 101
• Independent Samples
• Case 1 (t-test)
• Case 2 (Welch's test)
Example - Boys' shoes
• Remarks

• INFERENCE FOR COUNT DATA
• 4-2-3.html
• Sampling Distribution of a Sample Proportion
• Confidence Intervals and tests for Proportions
Example - Confidence interval
Example - Sample size
Example - Hypothesis Test
• Confidence Interval for the Difference Between Two Proportions
Example - City/country market survey

• 4-2-4.html
• Hypothesis Testing for Categorical Data
Example - Test-tube babies in Australia
Example - 3 out of 21 babies boys
Example - 50 coin tosses
• Testing more than 2 categories
• Remarks
P-values
Example - 60 throw fair die tester
• Comments

• 4-2-5.html
• Inference for Contingency Tables
Example - Vitamin C on colds
• General case:
Example - An homogeneous group of people
• MINITAB commands for chi-squared analysis

• MORE ON CORRELATION AND REGRESSION
• 4-2-6.html
• Use of Correlation and Regression
• Correlation and Correlation coefficient
Example - 20 female students in STAT101
Example - Health expenditure growth in Australia 1994-5
• Analysis of Variance
• Coefficient of Determination
Example on health expenditure continued

• 4-2-7.html
• Statistical Inference for Linear Regression
Example - Statistical model for predicting delivery time

• SUMMARY
• 4-2-8.html
• How To Choose The Appropriate Method For Statistical Inference
• 1 sample/group - 1 variable - continuous scale
• 2 samples/groups - 1 variable - continuous scale
• 1 sample/group - 2 variables - both continuous
• 1 sample - 1 variable - categorical
• 2 samples/groups - 1 variable - categorical
• 1 sample/group - 2 variables - categorical

• STATISTICAL CONTROL CHARTS

• 5-1-2.html
• Common and Special Causes of Variation
Walter Shewhart
• W. Edwards Deming
• Common Causes
• Special Causes

• 5-1-3.html
• Control Charts For Variables Data
• Rational Subgroups
Example - Variation In Percent Solids Test

• 5-1-4.html
• Case 1: µ, s known
Example - Air conditioner thermostats
• Case 2: µ, s not known
Example (continued) - Variation In Percent Solids

• 5-1-5.html
• Constructing a Control Chart
• Some Comments On Control Charts

• 5-1-6.html
• Tests for Special Causes
A point beyond control limits
Eight points in a row on one side of the line
A run of seven sample means steadily increasing or decreasing
Points hugging the centre line
Points hugging the control limits
Cycles

• 5-1-7.html
• Individuals Charts
• Moving Ranges
• 2s limits