4.6 Apportionment methods - what does it mean that two quantities (votes and seats) are in proportion (proportional)
In general, proportion says that two ratios (or fractions) are equal. For example:
\[\frac{1}{2} = \frac{2}{4}\]
1-out-of-2 is equal to 2-out-of-4
The ratios are the same, so they are in proportion (are proportional). When things are in proportion, then their relative sizes are the same.