Cambridge O Level Mathematics (Syllabus D) · Syllabus 4024 · Statistics
Averages and Measures of Spread
What is Averages and Measures of Spread?
The four summary statistics of Cambridge O Level Mathematics 4024. The mean is the sum of the values divided by how many there are, and for a frequency table it is the sum of f times x divided by the sum of f. The median is the middle value of the ordered data, averaged across the two central values when the count is even. The mode is the most frequent value or category. The range is the largest value minus the smallest. The first three describe where the data sits and the fourth describes how spread out it is, so a complete summary quotes one of each. For grouped data the class midpoint replaces the unknown individual values, which makes the resulting mean an estimate and makes the answer to a mode question a modal class interval.
This definition is part of the Statistics chapter in Cambridge O Level Mathematics (Syllabus D).