Mean, median and mode, and which one a data set actually calls for

What this note covers

1. Three different answers to the question 'what is typical?'
2. The mean, by hand and from a frequency table
3. Grouped data and the midpoint method
4. The median: ordering and the middle position
5. The mode, the modal class and categorical data
6. Skew, outliers and choosing the right measure
7. Working backwards and comparing two data sets
8. How measures of centre are examined, and what separates a top-band answer

8 sections · 12 key terms & formulas · 6 common mistakes