Given two points, the midpoint formula is given by the average of the two x values and the average of the two y values. Mathematically, this is represented as (x1+x2)/2 for the x value of the midpoint, and (y1+y2)/2 for the y value of the midpoint.
To apply the midpoint formula, one needs to know the values of two discrete points, each written in the form of (x, y). For example, take the points (0, 3) and (4, 11). The two x values are 0 and 4, so their average is 0 plus 4 or 2. The two y values are 3 and 11. Adding 3 to 11 and dividing that result by 2 gives 7. Write the midpoint value in coordinate notation by placing the average of the x and the average of the y values into a set of parentheses and separating the two values with a comma. The correct answer to this example is (2, 7).