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Chapter 1: Introduction and Graphical Displays
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Listed are some examples of quantitative variables: the square footage of a
house, the systolic blood pressure of a patient, the time it takes to complete
an exam, the miles per gallon reported for a vehicle, the height of a female
college basketball player etc.
Definition: Qualitative Variables
Qualitative variables are variables whose values can be placed into distinct
categories, according to some characteristic or attribute.
Listed are some examples of qualitative variables: political affiliation, eye
color, blood type, gender, the classifications (freshman, sophomore, junior,
senior, or graduate) of a college student, etc.
Definition: Discrete Variables
Discrete variables are variables that can assume values which can be
counted.
Following are some examples of discrete variables: number of days it rained
during your spring break, number of children in a family, number of
defective items in a sample of 100 items, number of illegal parking tickets
issued on a college campus during a semester, number of persons attending
the final four basketball games etc.
Definition: Continuous Variables
Continuous variables are variables than can assume all values between any
two given values.
Following are some examples of continuous variables: amount of rainfall
during your spring break, height of an NBA basketball player, time it takes
to perform a triple bypass heart surgery, weight of a randomly selected
backpack belonging to a college student, the square footage of a building
etc.