IGCSE Math RevisionEdexcel IGCSE Maths (4MA1) · Revision notes · Statistical Reasoning
IGCSE Maths Statistics and Probability Revision Notes
Short, plain-English notes on data representation & probability for Pearson Edexcel International GCSE Mathematics A (4MA1), Higher tier. Each of the 3 sub-topics has what you need to know and one example with its answer. Cover the answer and try the example first, then practise the topic with worked solutions.
Statistical Measures
Mean, median, mode and range for raw, discrete and grouped data.
Mean = total ÷ count. Median = middle when ordered. Mode = most common. Range = max − min.
Example: Median + range of −3, 4, 7, 1, −1, 9, 5.
Answer: Ordered: −3, −1, 1, 4, 5, 7, 9. Median = 4 (the 4th of 7 values). Range = 9 − (−3) = 12.
Practise it: Mean, Median and Mode questions and answers
Histograms & Frequency Density
Drawing and reading histograms with unequal class widths using frequency density.
In a histogram the bar AREA shows the frequency: frequency density = frequency ÷ class width.
Example: A class 10 < x ≤ 25 has frequency 30. Find its frequency density.
Answer: 30 ÷ 15 = 2.
Practise it: Histograms and Cumulative Frequency questions and answers
Probability
Independent and mutually exclusive events, tree diagrams, with and without replacement.
Multiply along the branches of a tree diagram, add the paths you want. Without replacement, the numbers on the second branches change.
Example: A bag has 3 red and 5 blue counters. Two are taken without replacement. P(both red)?
Answer: 3/8 × 2/7 = 6/56 = 3/28.
Practise it: Probability questions and answers · Tree Diagrams and Conditional Probability questions and answers
More statistics and probability questions
Keep revising
- IGCSE Maths questions by topic: worked examples and exam-style questions with mark schemes
- Student hub: practise every unit, with each question marked
- IGCSE Maths formula sheet
- Edexcel IGCSE Maths 4MA1 past papers and the 4MA1 examiner report summary