


Proportion BasicsA proportion is a special form of an algebra equation. It is used to compare two ratios or make equivalent fractions. A ratio is a comparison between two values. Such as the following: 1 apple: 3 oranges This ratio compares apples to oranges. It means for every apple there are 3 oranges. A proportion will help you solve problems like the one below. Jane has a box of apples and oranges in the ratio of 2:3. If she has six apples, how many oranges does she have? Before we begin to set up proportions for a word problem, we will concentrate on solving proportions. Remember, a proportion is a comparison between two ratios. The proportion shown below compares two ratios which are in the fraction form. 1 x  =  2 6 The four parts of the proportion are separated into two groups, the means and the extremes, based on their arrangement in the proportion. Reading from lefttoright and toptobottom, the extremes are the very first number, and the very last number. This can be remembered because they are at the extreme beginning and the extreme end. Reading from lefttoright and toptobottom, the means are the second and third numbers. Remembering that "mean" is a type of average may help you remember that the means of a proportion are "in the middle" when reading lefttoright, toptobottom. Both the means and the extremes are illustrated below. Proceed to the next page to learn how to use the means and extremes to solve a proportion. 

