Question

Type the correct answer in the box. Use numerals instead of words. If necessary, use / for the fraction bar.
Find the missing number in this proportion.

30
Division Line = Division Line
90 18

Answer 1

To find the missing number in the proportion \( \frac{30}{90} = \frac{x}{18} \), we can cross-multiply:

\[
30 \cdot 18 = 90 \cdot x
\]

Calculating the left side:

\[
30 \cdot 18 = 540
\]

So, the equation becomes:

\[
540 = 90 \cdot x
\]

Now, we divide both sides by 90 to solve for \( x \):

\[
x = \frac{540}{90}
\]

Simplifying the fraction:

\[
x = 6
\]

Therefore, the missing number is \( 6 \).