Worksheet #1

STA 291-021

6/11/08

Terminology

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 population/sample

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?

Example

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…

Population

Elementary Unit

Sample

Parameter

Statistic

An example of Descriptive Statistics

An example of Inferential Statistics

Is the variable in this passage qualitative or quantitative?

Discrete or Continuous?