Answer
$$
\varepsilon=0.185 \quad \quad \text { or } \quad \quad 18.5 \%
$$
Work Step by Step
Using Eq. $20-11$, we find that the efficiency is
$$
\varepsilon=\frac{|W|}{\left|Q_{\mathrm{H}}\right|}=\frac{4.73 \times 10^{3}}{25.5 \times 10^{3}}=0.185 \quad \text { or } \quad 18.5 \%
$$
