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Mathematics vocabulary · Word Problems

Proportional

Meaning in mathematics, with examples

/prəˈpɔːrʃənəl/adjectiveCommon term

In mathematics, proportional means: Changing together with another quantity so that their ratio stays fixed; if y is proportional to x, doubling x also doubles y.

In Turkish: orantılı

How it is used

Common phrases are 'directly proportional to' (y = kx) and 'inversely proportional to' (y = k/x), where k is the constant of proportionality. The symbol ∝ is read 'is proportional to'.

Example sentences

  1. The cost is directly proportional to the number of kilograms you buy.

  2. For a fixed distance, the time taken is inversely proportional to the speed.

Common collocations

  • directly proportional to
  • inversely proportional to
  • constant of proportionality
  • proportional to
  • ratioA comparison of two or more quantities that shows how big one is compared with the other, written like 3:2 and read 'three to two'.
  • rateA ratio that compares two quantities measured in different units, such as kilometres per hour or litres per minute.
  • linearRelated to a straight line; a linear equation or function has no power of the variable higher than 1, so its graph is a straight line.
  • word problemA maths question written as a short story or real-life situation, which you must turn into numbers or equations before solving it.

More terms: Word Problems

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