Which of the following describes a ratio?

A ratio is fundamentally a comparison of two quantities that illustrates the proportional relationship between them. This is achieved through division, where one quantity is divided by another to determine how many times one number contains the other. For example, if there are 3 apples and 6 oranges, the ratio of apples to oranges can be expressed as 3:6, which simplifies to 1:2 when both numbers are divided by 3. This highlights the comparative aspect characteristic of ratios.

The other options do not accurately define a ratio:

• The sum of two numbers describes an addition operation, not a comparison of two quantities.

• A numerical value represented as a decimal pertains to a specific format rather than the relationship between two distinct quantities.

• A method for calculating percentages involves a different mathematical concept focused on expressing a number as a fraction of 100, rather than comparing two quantities directly.

Thus, the correct answer effectively captures the essence of what a ratio represents in mathematics.