The midpoint of the segment RS is point M (5, 3). Therefore, the average of the x coordinates of R and S is 5, and the average of the y coordinates of R and S is 3. The x coordinate of R is 4. For 4 and the x coordinate of S to have an average of 5, the x coordinate of S must be 6. Therefore, our point is of the form (6, y). For 8 and the y coordinate of S to have an average of 3, the y coordinate of S must be -2. Therefore, our answer is (6, -2)
