The coefficient of volumetric thermal expansion of an isotropic solid is $\beta = 5.40 \times 10^{-5} \text{ } ^\circ\text{C}^{-1}$. What is the linear expansion coefficient $\alpha$ of this solid in $^\circ\text{F}^{-1}$? (Note: $\beta = 3\alpha$ for isotropic solids, and a temperature difference of $1 ^\circ\text{C} = 1.8 ^\circ\text{F}$)