Calculation Errors:
- ❌ Wrong quartile method: Including/excluding median incorrectly
- ❌ Unsorted data: Not arranging data in order first
- ❌ Mixed up quartiles: Q1 should be smaller than Q3
Drawing Errors:
- ❌ Wrong scale: Not using consistent spacing
- ❌ Box proportions: Making box too wide or narrow
- ❌ Median outside box: Median must be inside the Q1-Q3 box
Interpretation Errors:
- ❌ Confusing IQR with range: IQR is Q3-Q1, range is max-min
- ❌ Overinterpreting small differences: Consider the context and scale
- ❌ Ignoring outliers: Outliers can significantly affect conclusions
This exam tips covers Common Mistakes to Avoid within Box Plots for GCSE Mathematics. Revise Box Plots in Statistics for GCSE Mathematics with 18 exam-style questions and 20 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 10 of 11 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
Practice questions for Box Plots
On a box plot, what does the box (the rectangle) represent?
Two athletics clubs record the 100m sprint times (in seconds) for their members. The five-number summaries are shown below. Club A: Min = 11.2, Q1 = 12.4, Median = 13.1, Q3 = 14.2, Max = 16.5 Club B: Min = 12.0, Q1 = 13.5, Median = 14.8, Q3 = 16.1, Max = 17.3 Compare the distributions of sprint times for the two clubs. You must use the data to support your answer. (3 marks)