The point-slope form of the equation of a line is given by:
\[ y - y_1 = m(x - x_1) \]
where \( m \) is the slope and \( (x_1, y_1) \) is a point on the line.
Here, the slope \( m \) is \( \frac{1}{2} \) and the point \( (x_1, y_1) \) is \( (4, 8) \).
Substituting these values into the point-slope form, we get:
\[ y - 8 = \frac{1}{2}(x - 4) \]
This is the equation of the line in point-slope form.