Solution:
1. Understand the given proportion:
- We have the proportion \frac{x}{15} = \frac{30}{9}.
2. Cross-multiply to solve for x:
- x \cdot 9 = 15 \cdot 30.
3. Simplify the equation:
- 9x = 450.
4. Solve for x:
- Divide both sides by 9 to isolate x, x = \frac{450}{9}.
- Calculate x, x = 50.
Therefore, the value of x is 50.