[tex] \frac{4 {x}^{2} }{ {x}^{3} } = \frac{16}{ {x}^{2} } \\ = > \frac{4}{x} = \frac{16}{ {x}^{2} } \\ = > 4 = \frac{16}{ {x}^{2} } \times x \\ = > 4 = \frac{16}{x} \\ = > x = \frac{16}{4} \\ = > x = 4[/tex]
The answer is 4.