Statistics and data analysis.
Make fair statistical comparisons, read and create displays, and judge what evidence can support. Includes explicit quartile and standard-deviation conventions, paired-data investigations and three progressive topic papers.
Work through the topic
Learn the method, follow the examples, then try the worksheet.
- 01
Mean, median and range in continuous distributions
Choose and calculate a sensible measure of centre or spread for measured data, and distinguish exact raw-data results from grouped estimates.
- 02
Quartiles and five-number summaries
Build a five-number summary using a stated quartile convention and use it to describe measured data.
- 03
Interquartile range and box plots
Calculate interquartile range, draw readable box plots and compare typical values and variability.
- 04
Percentiles and cumulative frequencies
Interpret cumulative totals, locate percentiles and estimate positions within grouped measurements.
- 05
Standard deviation
Use standard deviation to quantify spread around a mean and distinguish population from sample calculations.
- 06
Comparing distributions
Compare distributions using several features without overstating what a graph or summary proves.
- 07
Scatterplots
Create scatterplots from paired observations and distinguish a relationship graph from separate unpaired lists.
- 08
Direction/strength/form of association
Describe an association by its direction, strength and form, and recognise outliers and curved patterns.
- 09
Association versus causation
Distinguish an observed association from a causal explanation and identify plausible confounding variables.
- 10
Categorical two-way tables
Construct and interpret two-way tables using counts and conditional percentages for categorical variables.
- 11
Misleading claims and bias
Spot how selection, questions, axes and missing context can make a statistical claim misleading.
- 12
A bivariate investigation and its limitations
Plan and carry out a small bivariate investigation, then report the pattern and the limits of the evidence.
Topic review
Revisit the key ideas, then choose a practice paper.