Grouped Data
Grouped data is raw data that has been organized into groups or class intervals to simplify analysis and interpretation. Instead of listing every single observation, the data is condensed into a frequency distribution table showing how many observations fall within each specific range.
Key Concepts
Data is divided into continuous or discontinuous groups called class intervals, such as 0-10, 10-20, and 20-30.
The number of observations falling within a particular class interval is known as its frequency.
To perform statistical calculations, the midpoint of each class interval, called the class mark, is used to represent all values in that group.
Real World Applications
A teacher organizing the test scores of 50 students into grade brackets (e.g., 40-50, 50-60) to quickly see how many students passed or failed.
A census department grouping the ages of a city's population into intervals (e.g., 0-10 years, 11-20 years) to analyze demographic trends.