Statistics
A-Level Statistics
Statistics covers data presentation, measures of location and spread, probability, and the binomial and normal distributions, plus hypothesis testing.
What you need to know
- Mean, median, quartiles, variance and standard deviation
- Outliers and box plots
- Binomial and normal distribution calculations
- Hypothesis testing and the meaning of a p-value
Key concepts
- A binomial model needs a fixed number of independent trials with constant probability.
- The null hypothesis is what you assume true until the evidence is strong enough.
- Correlation does not establish causation.
Common mistakes
- Comparing the p-value with the wrong tail for a two-tailed test
- Using n instead of n − 1 where the question specifies a sample
- Stating a conclusion without referring back to the context
Example question
Find the median of 4, 9, 2, 7, 5.
Show explanation
Ordered: 2, 4, 5, 7, 9. The middle value is 5.
Practise Statistics
5 original questions with worked explanations, mixed across easy, medium and challenging difficulty.
Statistics questions students ask
- Do I need the large data set?
- Yes. Each board sets contextual questions on its prescribed large data set, so familiarity with its variables and units is expected.