Formula for midpoint of two points: (x1+x2)/2, (y1+y2)/2. It doesn't matter what the order of the points are.
Plug in the values: (4-3)/2, (3+0)/2, the midpoint is (0.5, 1.5)
Formula for midpoint of two points: (x1+x2)/2, (y1+y2)/2. It doesn't matter what the order of the points are.
Plug in the values: (4-3)/2, (3+0)/2, the midpoint is (0.5, 1.5)