Use this proportion calculator to find missing values in proportional relationships. It uses two methods such as cross-multiplication and proportion formula to represent the equality between two ratios.
“When two ratios are set equal to each other, then it is called a proportion”
The symbol of proportion is ‘::’ and ‘=’.
Two variables are said to be directly proportional if one variable is equal to the product of the other variable and a constant. If the product of the two variables is a constant, then they are said inversely proportional ( x·y is a constant).
The formula for proportion is stated as:
a:b::c:d=\(\frac{a}{b}=\frac{c}{d}\)
There are two main and easiest ways to solve proportions:
We have used both in the given example for better understanding:
The two ratios are 8:?::6:4, solve for the unknown variable x.
Solution:
Using Cross Multiplication:
Step #1: Construct a Proportion
\(\frac{8}{x}=\frac{6}{4}\)
Step 2: Apply Cross Multiplication
\(\ x\ \times\ 6=\ 8\ \times\ 4\)
\(\ 6x= 32\)
\(\ x=\frac{32}{6}\)
\(\ x=\frac{16}{3}= 5.33…\)
Using The Proportion Formula:
a:b::c:d=\(\frac{a}{b}=\frac{c}{d}\)
\(\frac{8}{x}=\frac{6}{4}\)
\(\frac{8}{x}=\ 1.5\)
\(\ x =\frac{8}{1.5} = 5.33..\)
\(\ x = 5.33..\)
In this example, we have found the proportion manually. But for more complex problems, you can use the above proportion calculator.