Chapter 1
Def’n: Statistics:
1) are commonly known as numerical facts
2) is a field of discipline or study
Here, statistics
is about variation.
3 main aspects of statistics:
1) Design (“Think”): Planning how to obtain data to answer questions.
2) Description (“Show”): Summarizing the obtained data.
3) Inference (“Tell”): Making decisions and predictions based on data.
Chapter 2  Data
Def’n: A population
consists of all elements whose characteristics are being studied.
e.g. UofA students
A sample
is a portion of the population selected for study.
e.g. UofA students in this section
A parameter
is a summary measure calculated for population data.
A statistic
is a summary measure calculated for sample data.
Types of statistics:
Descriptive: methods to view a given dataset.
e.g. averages, histograms
Inferential: methods using sample results to infer conclusions about a larger population.
e.g. ttests, simple linear regression
Def’n: A variable
is any characteristic that is recorded for subjects in a study.
 Qualitative (categorical): cannot assume a numerical value but classifiable into 2 or
more nonnumeric categories. e.g. gender, smell, grades
 Quantitative (numerical): measured numerically.
 Discrete: only certain values with no intermediate values.
e.g. integers, grades
 Continuous: any numerical value over a certain interval or intervals.
e.g. GPA, gas prices
Chapter 3 – Categorical Data Graphs
Def’n: A frequency table
(for qualitative data) is a listing of possible values for a
variable, together with the # of observations for each value.
Major
Frequency (
f
)
Relative frequency
Percentage (%)
Science
Arts
Business
Nursing
Other
Relative frequency
∑
=
f
f
Percentage
=
Relative frequency
× 100%
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Def’n: A bar chart
is a graph of bars whose heights represent the (relative) frequencies of
respective categories. e.g. (preceding table used in class)
Look for
: frequently and infrequently occurring categories.
A pie chart
is a circle divided into portions that represent (relative) frequency
belonging to different categories. e.g. (preceding table used in class)
Look for
: categories that form large and small proportions of the data set.
A segmented bar chart
uses a rectangular bar divided into segments that represent
frequency or relative freq. of different categories.
e.g. (preceding table used in class)
Chapter 4 – Numerical Variable Graphs
Def’n: A stemandleaf display
has each value divided into two portions: a stem and a
leaf.
The leaves for each stem are shown separately.
(Values should be ranked.)
Look for
:  typical values and corresponding spread
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 Winter '10
 PaulCartledge
 Statistics, Standard Deviation, Yi

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