Answer
.032
Work Step by Step
We use the equation that relates the decibel level to intensity to find:
$\beta_1 - \beta_2 = 10logP_2-10logP_1$
$\beta_1 - \beta_2 = 10log\frac{P_2}{P_1}$
$\frac{\beta_1 - \beta_2}{10} = log\frac{P_2}{P_1}$
$\frac{P_2}{P_1} = 10^{\frac{\beta_1 - \beta_2}{10}}$
$\frac{P_2}{P_1} = 10^{\frac{60 -75}{10}}$
$\frac{P_2}{P_1} = .032 $
