What type of variable is represented by a range of dollar amounts such as annual income?

Annual income is a quantitative variable that represents a range of dollar amounts, making it a continuous measure. The best fit among the provided options is the interval variable. Interval variables have meaningful intervals between measurements, allowing for a comparison of values in terms of the amount of difference.

In the case of annual income, we can determine that one income is greater than or less than another, and the differences (such as the difference between $50,000 and $60,000) have significant meaning. Income also does not have a true zero point in the context used, although it can represent zero income; zero here does not indicate the absence of income in a mathematical sense like in a ratio scale.

Understanding this classification is vital as it helps determine which statistical methods are appropriate to use when analyzing the data. The choice of interval aligns with the nuances of income as a measurable, numeric variable where differences are meaningful.