Types of data

• Variables or data associated with numerical observations are called quantitive variables or quantities data
• Variables or data associated with non numerical observations are called qualitative variables or data
• A variable that can take any value in a given range is a continuous variable
• Is time discrete or continuous

  Continuous
• A variable that can take only specific values in a given range is a discrete variable
• Is the number of girls in a family discrete or continuous?

  Discrete
• Class boundaries tell you the maximum and minimum values that belong in each class
• The midpoint is the average of the class boundaires
• Class width is the difference between upper and lower class boundaries