To find the midpoint \( M \) of the line segment with endpoints \( J(1.2, 3.4) \) and \( K(4.8, -2.3) \), we can use the midpoint formula:
\[ M = \left(\frac{x_1 + x_2}{2}, \frac{y_1 + y_2}{2}\right) \]
where \( (x_1, y_1) \) are the coordinates of point \( J \) and \( (x_2, y_2) \) are the coordinates of point \( K \).
Plugging in the values from points \( J \) and \( K \):
- \( x_1 = 1.2 \)
- \( y_1 = 3.4 \)
- \( x_2 = 4.8 \)
- \( y_2 = -2.3 \)
Calculating the \( x \)-coordinate of the midpoint:
\[ \frac{x_1 + x_2}{2} = \frac{1.2 + 4.8}{2} = \frac{6.0}{2} = 3.0 \]
Calculating the \( y \)-coordinate of the midpoint:
\[ \frac{y_1 + y_2}{2} = \frac{3.4 + (-2.3)}{2} = \frac{3.4 - 2.3}{2} = \frac{1.1}{2} = 0.55 \]
So, the coordinates of the midpoint \( M \) are:
\[ M = (3.0, 0.55) \]
Therefore, the midpoint \( M \) of segment \( JK \) is at \( (3.0, 0.55) \).