Objective and Scope of Statistics
Study Design, Types of Studies, Variables
Bias, Sample Size Issues
Data Classification
Homework problems
1.1
o
Statistics is the science of learning
from data.
o
Statistics involves collecting,
presenting, analysing and i

Bar charts & pie charts
Histograms
Box plots
Scatter plots
2.1
o We covered some basic principles of study design and
looked briefly at some sampling issues.
o We looked at different types of studies:
o observational studies are those in which there
is no

Using the least squares regression line
to make predictions
Goodness-of-fit statistic
Correlation coefficient
10.1
We examined the relation between two numerical variables by:
o selecting the response variable,Y, and the determinant (or
predictor) variabl

Scatter plots - relations between numerical variables
Dependent and independent variables
The least squares regression line
Assumptions of the linear model
Testing the slope of the least squares regression line
9.1
o We compared population means:
o We use

Confidence interval for , the population mean
o known
o unknown (using the t-distribution)
Confidence interval for , the population
proportion
6.1
We looked at the distribution of sample means and sample
proportions in repeated sampling. We found that:
o

Solutions to the Homework
problems for Week 5
5.55
Homework Problem 1
Sheilas doctor is concerned that she may suffer from gestational
diabetes (high blood glucose levels during pregnancy). There is variation
in both the actual glucose level and blood tes

Population distributions
Summarising Numerical Data
o Measures of centre and spread
Summarising Categorical data
o Proportions and Percentages
3.1
We considered various ways of graphing data.
o Bar charts and pie charts are used to display categorical
dat

One sample z-test for a population
mean ( known)
One sample t-test for a population
mean ( unknown)
7.1
o A 95% confidence interval is an interval which we
believe, with 95% confidence, will contain the value of
the population parameter of interest.
o The

Solutions to the Homework
problems for Week 4
4.59
Homework Problem 1
A bank audit on 30/6/2009 recorded the balances of a
number of school savings accounts. It was found that
the balances followed a normal distribution with a
mean of $230 and a standard

Solutions to the Homework
problems for Week 3
3.55
Homework Problem 1
Consider the variables outlined on the next slide.
For each variable measured, draw a rough diagram of
what you think the resulting population distribution
will look like.
3.56Q
Stat170

Homework Questions
7.45
a) The one-sample t statistic for testing
H0: = 40
H1: 40
from a sample of n = 28 observations has the value
t = 2.01
(i) What are the degrees of freedom?
(ii) Between what two values does the p-value of the
test fall?
(iii) Based

Homework Questions
Dont forget to try these!
8.39
For the following five problems, determine whether the
correct analysis would be a paired t-test (assuming
differences were drawn from a normal distribution) or a
two sample t-test (assuming both samples w

Homework Questions
10.30
A trial was undertaken to test a new drug
for allergies. Ten allergy sufferers were
given various doses of the drug to determine the
relation between the dosage (milligrams) and the
duration of relief from allergic symptoms (hours

o Unit Review
o Past Examination Questions
13.1
Research Questions
We use a
SAMPLE to
answer
questions
about a target
POPULATION
?
?
?
Population
13.2
estimate
Sample Statistics
Population Parameters
Mean
Median
Std.Dev
Variance
2
2
se(mean)
Proportion
1

Introduction to probability
The normal distribution
The standard normal distribution
Areas under a normal curve
z-scores and probability
Percentiles for a normal distribution
4.1
o We looked at summarising data.
o The most basic measures summarising numer

Paired data
Independent data
8.1
o We worked through hypothesis tests for a population mean to answer
research questions about a target population.
o We tested a null hypothesis: H0: = 0 against an
alternative hypothesis: H1: 0
o We used a z-test when was

Review of the normal curve
The behaviour of sample means
The behaviour of sample proportions
5.1
Review of the normal curve
5.2
o The standard normal distribution has a mean of 0
and standard deviation of 1. Any normal distribution
can be standardised:
=

One sample z-test for a Population
Proportion
Chi-Squared 2 Goodness-of-Fit Test
11.1
o We found that, under certain conditions, the least
squares regression model can be used to make
predictions.
o The goodness-of-fit statistic (r2) is a measure of how
w

Homework Questions
11.37
Do consumer preferences for Brand A
cola and Brand B cola differ?
A sample of 75 people take part in an experiment
to compare two different brands of cola flavoured soft
drink. Each person is blindfolded and given a small drink
of

Chi-Square Test of Independence
Some Summaries
12.1
o We analysed a categorical variable using a z
distribution and using a 2 distribution.
o A categorical variable with two categories or groups
(ie. a binary variable) can be analysed using either a ztest