How to Find Out Whether Ratios Are Proportional

A calculator can help you determine if ratios are proportional.

Ratios measure the relationship between two numbers, such as the number of hits a batter gets per the number of times he bats or the number of strikes a pitcher throws per the number of total pitches she throws. Two ratios are considered proportional when the relationship between the two numbers is the same. For example, in the ratio 1:4, the relationship is multiplying the first number by four. In the ratio 4:16, even though the numbers are different, the relationship is still multiply the first number by 4. Therefore, 1:4 and 4:16 are proportional.

Things You'll Need

• Calculator

Instructions

1. Convert each ratio to a proportion by placing the first number in the ratio over the second. For example, if your ratios are 6:18 and 11:33, you would get the fractions 6/18 and 11/33.

2. Multiply the numerator of the first fraction by the denominator of the second fraction. In this example, multiply 6 by 33 to get 198.

3. Multiply the numerator of the second fraction by the denominator of the first fraction. In this example, multiply 18 by 11 to get 198.

4. Compare the results of Step 2 and Step 3. If the two results are equal, the ratios are proportional. If they are unequal, the ratios are not proportional. In this example, the results from Step 2 and Step 3 both equal 198, so 6:18 is proportional to 11:33.

References

• Nelson Education: Recognizing a Proportional Situation