Answer : The y-coordinate of the midpoint of a vertical line segment is, 7.5
Step by step explanation :
The method used to calculate the y-coordinate of the midpoint of a vertical line segment is, Mid-point formula.
If a line segment AB with endpoints at
and

The mid-point formula will be,

Now we have to calculate the x-coordinates and y-coordinates.
The given endpoints are, (0, 0) and (0, 15)



The x-coordinate of the midpoint of a vertical line segment is, 0
The y-coordinate of the midpoint of a vertical line segment is, 7.5
Therefore, the y-coordinate of the midpoint of a vertical line segment is, 7.5