When two variables are proportional, doubling one doubles the other.

A large proportion of the students volunteered for the clean-up.

The architect designed a well-proportioned façade that complemented the surrounding buildings.

On the exam, the item required a proportional analogy, such as 'bird is to nest as bee is to hive,' to demonstrate students' understanding of relational reasoning.

The antique algebra text listed several means proportional between segments, though the notation is archaic.

The mean proportional between a and b is the square root of ab.

When solving classical construction problems, mathematicians searched for techniques to construct mean proportionals between two segments.

Using a compound proportion, she demonstrated that the product of the three rates was proportional to the product of the three durations.

Students solved a set of compound proportions to determine how the ingredients should be scaled for the recipe.

In physics class, we learned that pressure and volume are connected by a reciprocal proportion.