Calculate averages

Calculate averages for discrete and grouped data: mode, median, arithmetic mean, weighted mean, geometric mean, mean seasonal variation.
The term ‘mean’ should be understood to be ‘arithmetic mean’ unless ‘geometric mean’ is stated.

Calculations of mean and median for grouped data will include equal or unequal class widths. Linear interpolation for median is expected.
Use of class midpoints (mid-interval values) to estimate mean of grouped data is expected.
Understand the effect on the mean, mode and median of changes in the data, including the addition or withdrawal of a population or sample member.
Understand the effect of transformations of the data on the mean, mode and median. (Transformations will be restricted to simple scaling and translations.)