I'm not sure about ratios, because I'm bad at them myself, but I can help you with graphs. Take this plot point, for example (3,4) The X-axis is the line that is horizontal. This is the first letter in the coordinates, 3, so you would find the number 3 on the X-axis. The Y-axis is the line that is vertical, and its number is the second one in your set of coordinates. You would then find 4 on your Y-axis. Then, draw a line from your X-coordinate up, and your Y-coordinate right. Find where these overlap. If these are negatives, however (for example, if the coordinates were (-3,-4)), then draw the line in the opposite direction (X-coordinate down, Y-coordinate left) and do the same as you would with normal coordinates and find where they overlapped. I hope this helped you, since I love graphs and want to help!
