What is the term used to describe a comparison of two quantities by division?

The term that describes a comparison of two quantities by division is known as a ratio. A ratio expresses how much of one quantity exists in relation to another, typically written in the form of “a to b” or as a fraction (a/b). Ratios are commonly used in mathematics and various fields to determine relationships, such as comparing distances, speeds, or quantities in recipes.

Understanding ratios is fundamental, as they can provide insight into the relative sizes of different quantities, allowing for easier interpretation of data. This term is distinct from a rate, which typically involves a comparison of quantities with different units (like miles per hour), or a proportion, which denotes that two ratios are equal. A fraction, on the other hand, represents a part of a whole rather than a direct comparison of two separate quantities. Thus, the definition and application of a ratio clearly establish it as the correct choice in this context.