grouping data

• Grouping data using tables makes it easier to spot patterns in the data and quickly see how the data is distributed
• Discrete data can be grouped into classes that do not overlap e.g. 0-10, 11-15… (they do not have to have equal class width). Uses smaller intervals when there is a lot of data close together in that range and wider classes for data that is more spread out.
• Continuous data can be grouped using inequalities. The class intervals must not have gaps between them or be overlapping so inequality symbols must be used with one of the symbols being < and the other ≤.
• Pros: Makes the data easy to read and understand. Easy to spot patterns and compare data.
• Cons: Loses accuracy of data as you no longer know exact data values. Calculations made from these will only be an estimate e.g. mean.