Which of the following is a numeric variable?

• A. Hours studied.
• B. Academic major.
• C. Class year.
• D. Gender.

Answer: (A)

Distinguishing numeric (quantitative) variables from categorical ones is what this item is about. A numeric variable represents a measurable quantity on a numeric scale, so its values are numbers you can add, average, or compute differences with. Hours studied fits this because it records the amount of time spent studying, a quantity that can be summed and averaged across students.

The other options are categories rather than measurements on a numeric scale. Academic major is a category describing fields of study. Class year designates a standing in a sequence (freshman, sophomore, etc.) and is usually treated as an ordered category rather than a measured quantity. Gender is another category used for grouping. Although sometimes numbers are used as labels, those labels don’t inherently provide a numeric scale for analysis in the way hours studied does.

So hours studied is the numeric variable because it is a measurable quantity expressed with numbers that allow arithmetic operations and meaningful statistics.