STA 291 (022-024)
Fall 2009
Population – Total set of all subjects of interest
Elementary Unit – Any individual member of the population
Sample – Subset of the population from which the study actually collects information
Variable – A characteristic of a unit that can vary among subjects in the
Parameter – Numerical characteristic of the population
Statistic – Numerical characteristic of the sample
Descriptive Statistics – Summarizing the information in a collection of data
Inferential Statistics – Using information from a sample to make conclusions/predictions
about the population
Qualitative Variable – Variable without numerical values associated with them
Nominal – scale of unordered categories
Ordinal – scale of ordered categories
Quantitative Variable – Variable with numerical values associated with them
Scale of measurement is Ordinal
Discrete Variable – takes on a finite number of values
Continuous Variable – takes on an infinite continuum of possible real number values
Ask yourself, can you be more specific? Can you find a value in between?
Suppose a UK student, we’ll call him George, wants to conduct a survey about Kentucky
High School students and hands out his survey to high school students at Lexington
Catholic, Henry Clay, and Paul Laurence Dunbar. From a study in 2005, it was already
known that 82% of high school students in Kentucky said they were going to apply to go
to college. George’s survey revealed that 64% of the students were going to apply to go
to college. George used the information from his survey to determine that at least 60%
of high school students in Kentucky were going to apply to go to college.
Identify the following…
Elementary Unit
An example of Descriptive Statistics
An example of Inferential Statistics
Is the variable qualitative or quantitative?
Is the variable Discrete or Continuous?