Answer
See explanation.
Work Step by Step
Equation 16.14 relates the sound intensity $I$ and the pressure amplitude $p_{max}$.
$$I=\frac{p_{max}^2}{2\sqrt{\rho B}}$$
If the pressure amplitude is halved, the intensity is reduced by a factor of 4, i.e., it is one-fourth of its old value.
To increase the intensity by a factor of 16, the pressure amplitude must be increased by a factor of 4.
