Glossary
proportion
A proportion states that two ratios are equal, such as 3/4 = 12/16. Solve it by cross-multiplying: multiply the two diagonals and set them equal.
A proportion is a statement that two ratios are equal: 3/4 = 12/16, or 200 miles in 4 hours equals 350 miles in 7 hours. Where a ratio compares two quantities, a proportion puts two ratios side by side and says they are in balance — one pair is a scaled copy of the other.
Solving one is a single move. Cross-multiply the two diagonals and set the products equal: if 3/4 = x/16, then 4x = 48 and x = 12. That works because both ratios can be thought of as fractions; multiply each side by both denominators and the fractions clear.
Setting a proportion up correctly is where the points are won or lost. Line up the two quantities in the same order on both sides — dollars over hours on the left means dollars over hours on the right. Mixing the order is the standard error, and a question can usually be checked against common sense: if the answer says a car travels fewer miles in more time, the proportion was written upside down.
Taught in
Related terms
- ratio — A ratio compares two quantities by division — 3 to 4, 3:4 and 3/4 are the same ratio. It says how many of one thing there are for each of the other, not how many in total.
Source: Official ASVAB — subtest descriptions (what each subtest asks) and the CAT-ASVAB scored-question counts (accessed 2026-09)