in proportion of something—in terms of how much there is of each thing (in a combination):
- Make a syrup of the sugar and water in proportion of a pint of sugar to a quart of water…
in proportion to something—
1. as compared with smth.; considered with reference to smth.:
- His expenditure on pleasure and luxuries is rather high in proportion to his income.
2. corresponding to smth. in degree or amount:
- The subjects ought to contribute towards the support of the government in proportion to their respective abilities.