The slope of line \( e \) given by the equation \( y = \frac{3}{5} x + 8 \) is \( \frac{3}{5} \).
Since line \( f \) is parallel to line \( e \), it will have the same slope. Therefore, the slope of line \( f \) is also
\[ \frac{3}{5}. \]
Thus, the slope of line \( f \) is \( \frac{3}{5} \).