1. The problem is to solve the equation $4 = \frac{x}{ }$ where the denominator is missing. 2. Since the denominator is not provided, we cannot solve for $x$ directly. 3. If the denominator is assumed to be 1, then $4 = \frac{x}{1}$ which implies $x = 4$. 4. Without the denominator, the problem is incomplete and cannot be solved uniquely. 5. Please provide the denominator to proceed with solving for $x$.