6:x=36:30

To solve the proportion \( \frac{6}{x} = \frac{36}{30} \), we can use cross-multiplication:

\[ 6 \cdot 30 = 36 \cdot x \]

This simplifies to:

\[ 180 = 36x \]

Next, we can solve for \( x \) by dividing both sides by 36:

\[ x = \frac{180}{36} \]

Calculating the right side:

\[ x = 5 \]

Thus, the value of \( x \) is \( 5 \).