Which best describes a ratio?

• A. The proportion of deaths in total population
• B. A measure with a time component
• C. The number of new cases in a period
• D. Dividing one quantity by another, no specified relationship between numerator and denominator

Answer: (D)

A ratio is simply a way to compare two quantities by dividing one by the other, without implying any specific relationship such as time or part-to-whole. It’s just a quotient that shows how many times larger or smaller one quantity is relative to the other. For example, comparing apples to oranges by division gives a ratio, but it doesn’t mandate a time frame or that one quantity is a portion of a total.

This makes the direct definition—dividing one quantity by another with no specified relationship—the best description. The other concepts involve additional structure: a proportion ties a part to a whole (part over the total population), a rate includes a time component (like events per person-time), and a count is simply a number, not a ratio.