Answer
$$x=529$$
Work Step by Step
To solve the proportion, we put the product of the means equal to the product of the extremes as follows:
$$\frac{243}{58.3}=\frac{x}{127}\Longrightarrow x\times 58.3= 243\times 127\Longrightarrow x=\frac{ 243\times 127}{58.3}=529.348 \approx 529$$
