In IB Mathematics: Applications and Interpretation SL, statistics and probability is the largest topic – the IB suggests 36 of the 150 teaching hours. It is also where AI SL students can bank reliable marks, because the questions follow clear patterns. What separates a 5 from a 7 here is rarely the calculation (the GDC does that). It is choosing the right test and writing the conclusion properly.
What AI SL statistics covers
- Collecting data: populations and samples, sampling methods, bias, outliers.
- Presenting data: histograms, box plots, cumulative frequency.
- Measures: mean, median, mode, quartiles, standard deviation – and what they say about the data.
- Bivariate data: scatter diagrams, Pearson's correlation coefficient (r), the least-squares regression line, and Spearman's rank correlation.
- Probability, including the binomial and normal distributions.
- Hypothesis testing: null and alternative hypotheses, significance levels and p-values; the χ² test for independence (contingency tables), the χ² goodness-of-fit test, and the t-test for comparing two means.
Regression and correlation: the marks students miss
- Interpret r in words: "strong positive linear correlation", not just "0.92".
- Use the regression line only within the data range. Predicting outside it (extrapolation) is unreliable, and questions often ask you to say so.
- Use the right line: y on x to predict y from x.
- Correlation is not causation. Expect a question on it.
- Spearman's measures whether the relationship is consistently increasing or decreasing, not necessarily linear – useful when data is ranked or clearly non-linear.
Hypothesis tests: a five-line template
Every test in AI SL can be set out the same way:
- H₀: (no association / data fits the model / means are equal)
- H₁: (there is an association / does not fit / means differ – one- or two-tailed)
- Test statistic and p-value (from the GDC), with degrees of freedom for χ²
- Compare: p-value with the significance level
- Conclusion in context: "There is sufficient evidence at the 5% level to conclude that choice of sport and gender are not independent."
Students lose marks on line 5 more than anywhere else: no context, or wording like "H₀ is true". A test never *proves* H₀; it only shows whether there is enough evidence to reject it.
The traps
- Writing hypotheses about the sample instead of the population.
- Degrees of freedom for a contingency table: (rows − 1)(columns − 1).
- Mixing up observed and expected frequencies.
- Comparing the test statistic with the significance level instead of the p-value (or critical value).
- Choosing a one-tailed test when the question implies two-tailed.
A study plan for AI SL statistics
- Weeks 1–2: descriptive statistics and interpretation – short written answers, not just numbers.
- Weeks 3–4: regression and correlation, with interpretation questions from past papers.
- Weeks 5–6: hypothesis tests using the five-line template until it is automatic.
- Then: mixed past-paper questions, timed, with the markscheme.
Statistics is also a popular area for the internal assessment. Our IA topic guide covers how to choose one.
How Maths Bodhi helps AI SL students
- A diagnostic to see whether marks are lost in choosing the test, using the GDC, or writing conclusions.
- The five-line template practised on real IB questions.
- GDC sessions on regression, χ² and t-tests, with the working the markscheme expects.
- Written feedback on interpretation answers – the part examiners reward most.
Ajay Vatsyayan (M.Tech, 14+ years teaching maths) teaches IB DP maths at Maths Bodhi and has taught students from schools across Gurgaon, including DPS International, GD Goenka World School, Suncity School and Pathways World School. Maths Bodhi is independent and not affiliated with any school. Read Ajay's profile, or see our AI SL course page and IB statistics tutor page.
Home sessions across Gurgaon – for example on Golf Course Road and in Sector 54 – or online. Book a free demo class.
Related: IB maths probability distributions, GDC skills for IB maths and the IB DP maths guide for Gurgaon families.
Topic hours verified against the current IB AI guide by the Maths Bodhi team (October 2026). Teaching plan reviewed by Ajay Vatsyayan.
Frequently asked questions
- How much of IB maths AI SL is statistics?
- Statistics and probability is the largest AI SL topic – the IB suggests 36 of the 150 teaching hours.
- Which hypothesis tests are in IB maths AI SL?
- The χ² test for independence, the χ² goodness-of-fit test and the t-test for comparing two population means, using p-values and significance levels.
- How do I write a hypothesis test conclusion in IB maths?
- Compare the p-value with the significance level, then state in context whether there is sufficient evidence to reject the null hypothesis – never say the null hypothesis is proved true.