A proportion is a statement that two ratios are equal. It compares two sets of quantities. In a proportion, the two ratios have to be equivalent, meaning that the fractions must simplify down to the same value. For example, "2/3 = 4/6" is a proportion, because both sides of the equation simplify down to 2/3. This shows that the ratio of 2 to 3 is equal to the ratio of 4 to 6.
