Statistics.
Plan statistical investigations, analyse distributions and report trustworthy comparisons using numerical evidence.
Work through the topic
Learn the method, follow the examples, then try the worksheet.
- 01
Statistical questions and the investigation cycle
Turn an everyday concern into a question that can be answered with variable data, then follow a complete statistical investigation.
- 02
Population versus sample
Identify the population, sample, parameter and statistic, and decide when a census is practical.
- 03
Sampling methods and bias
Choose and critique chance-based and convenience sampling methods.
- 04
Collecting/classifying data
Classify variables and apply consistent collection and cleaning rules.
- 05
Frequency tables and appropriate displays
Construct frequency tables and choose a display that matches the variable.
- 06
Shape, centre and spread
Describe distribution shape and interpret centre and spread together.
- 07
Quartiles and box plots
Calculate quartiles and interpret box plots using a stated convention.
- 08
Mean/median and variability
Use weighted means and distinguish measures of variability.
- 09
Comparing two or more groups
Compare groups using common scales and evidence about centre and spread.
- 10
Outliers and fair conclusions
Investigate unusual observations without hiding genuine extremes.
- 11
Communicating findings and limitations
Report a statistical finding with numerical evidence and realistic limitations.
Topic review
Revisit the key ideas, then choose a practice paper.