The thermal conductivity $k$ is $0.5 \text{ W/(m} \cdot \text{K)}$. Calculate its value in $\text{Btu} \cdot \text{in} / (\text{hr} \cdot \text{ft}^2 \cdot ^\circ\text{F})$. (Approximation: $1 \text{ W/mK} \approx 6.933 \text{ Btu} \cdot \text{in} / (\text{hr} \cdot \text{ft}^2 \cdot ^\circ\text{F})$)