STATISTICS: TYPES OF VARIABLES

Claire 12B

Qualitative Variables

A qualitative variable is a categorical variable that represents different groups and relates to non-numerical data like hair colors and favorite books.

1) Nominal Variables

A variable that divides the sample into different groups.

Examples

Gender: male and female

Marital status: unmarried and married

2) Ordinal Variables

An ordinal variable ranks or divides a sequence in order, but the intervals may not be the same.

Examples

Best student cities ranking

Best universities ranking

Customer satisfaction rate (very unsatisfactory, unsatisfactory, moderate, satisfactory, very satisfactory)

Quantitative Variables

A quantitative variable relates to numerical data and is measured on a quantitative scale. Examples include a country’s population and a book’s price.

1) Discrete Variables

A discrete variable can only take integers as its value, and its number of values is finite (limited). Examples include AP scoring scale (1-5) and SAT scoring scale (200-800). An AP score cannot be 4.5, and an SAT score cannot be 2345.4.

Examples

Number of countries in the world

Number of girls in a class

Number of cousins you have

Number of books you have

2) Continuous Variables

A continuous variable represents numerical data as accurately as possible.

Examples

Price of books Age of students in

a class Temperature

Quiz

1) If I divide a group of people into different sections based on their hair colors, is the variable qualitative? Quantitative?

2) If I rank the world universities, what kind of variable is it? Explain.

3) Explain four sub-groups of two types of variables.

Quiz 2

4) If I divide the test scores based on gender, what type of variable is it? (State specifically)

5) Can I use continuous variables to indicate the number of pencils I have? Why or why not?

Answers

1) Qualitative 2) Ordinal because it ranks the

universities with different intervals. 3) Qualitative (nominal, ordinal)

Quantitative (discrete, continuous) 4) Nominal (Qualitative) 5) No because only discrete variable can

be used to indicate countable numbers (integers) with limited value.