# How do I find the missing number in the following proportion? ___: 8 = 12:32

Nov 20, 2017

The missing number is $3$.

#### Explanation:

Think like this:

$\frac{x}{8} = \frac{12}{32}$

Cross multiply

$32 x = 96$

Divide both sides by $32$ to get

$x = 3$

Nov 20, 2017

See a solution process below:

#### Explanation:

We can call the number we are looking for $n$

We can now rewrite this problem as:

$\frac{n}{8} = \frac{12}{32}$

We can multiply each side of the equation by $\textcolor{red}{8}$ to solve for $n$ while keeping the equation balanced:

$\textcolor{red}{8} \times \frac{n}{8} = \textcolor{red}{8} \times \frac{12}{32}$

$\cancel{\textcolor{red}{8}} \times \frac{n}{\textcolor{red}{\cancel{\textcolor{b l a c k}{8}}}} = \cancel{\textcolor{red}{8}} \times \frac{12}{\textcolor{red}{\cancel{\textcolor{b l a c k}{32}}} 4}$

$n = \frac{12}{4}$

$n = 3$