Playbook
Statistics
80 q · 8% HARD · rising from 3.8 to 5.0 a paper. The cheapest chapter of any size: four of its six subtopics have never set a HARD question. Every question here is one to attempt.
- Questions in the bank
- 80
- q/paper (21 papers)
- 3.81
- Tagged HARD
- 8%
- Subtopics
- 6
Strand: Quick-Win
When you’ll see it
A table of data, a frequency distribution, or a question about mean, median or mode.
How this chapter is tested
80 questions and rising: 3.8 a paper in 2016-2020, 5.0 in 2024-2026. At 8% HARD it is the cheapest chapter of any size in the bank, and four of its six subtopics have never set a HARD question.
The HARD it has is in grouped data: the median and mode formulas for class intervals. The rest is reading a table correctly and knowing which average suits which data.
The sub-skills
The distinct skills inside the chapter, in the order to learn them.
Presenting data
Scales of measurement, and which chart suits which data.
Frequency tables
Cumulative frequency and class marks.
Mean and its properties
Adding c to every value adds c to the mean; deviations from the mean sum to zero.
Median and mode
Ungrouped: the middle value; grouped: l + ((n/2 − cf)/f) × h.
Traps to expect
Distractor shapes this chapter reuses. The Traps page covers the ones that cut across chapters.
Median of an even count
The average of the two middle values, after sorting.
Class width
Use the true width of the class, not the difference of the printed limits of a discontinuous table.
Learn it before you drill it
This chapter has full teaching notes — foundations, worked examples, self-checks and a mastery check for each subtopic. Read the notes once, then drill subtopic by subtopic below.
Statistics notesDrill every Statistics question
80 questions from the bank, across 6 subtopics.
Drill one subtopic at a time
The 6 subtopics, in teaching order.
- Data, Scales and PresentationDrill Data, Scales and Presentation
- Frequency Tables and Cumulative FrequencyDrill Frequency Tables and Cumulative Frequency
- Properties of the Arithmetic MeanDrill Properties of the Arithmetic Mean
- Median of Ungrouped DataDrill Median of Ungrouped Data
- Mean, Median and Mode of Grouped DataDrill Mean, Median and Mode of Grouped Data
- Choosing a Measure of Central TendencyDrill Choosing a Measure of Central Tendency
Related playbooks
Often paired with this one — the technique or the trap overlaps. Drill these next.