What is a ratio?

A ratio serves as a comparison between two quantities, demonstrating how many times one quantity contains or is contained within the other. It is specifically defined as a relationship established by dividing one quantity by another. For instance, if there are 3 apples and 6 oranges, the ratio of apples to oranges can be expressed as ( \frac{3}{6} ) or simplified to ( \frac{1}{2} ), indicating that for every apple, there are two oranges.

In contrast, the other options do not accurately represent a ratio. While the first option mentions a measurement of size, that refers more broadly to dimensions rather than a specific comparison between quantities. The second option discusses multiplication, which doesn't apply to how ratios function since they rely on division rather than that operation. The last option, which suggests a numerical representation of data, lacks the specific comparative aspect that defines a ratio. Thus, the characterization of a ratio as a comparison of two quantities by division is the most accurate representation of this mathematical concept.