A coordinate plane with a straight line with a positive slope. The line starts at (0, 0) and passes through points labeled A at (2, 1) and B at (4, 2) and through (8, 4). There is a vertical dashed line starting at point A extending two units to the right and one unit up to point B. What is the vertical change from Point A to Point B?

What is the horizontal change from Point A to Point B?

What is the rate of change shown on the graph? Give the answer as a decimal rounded to the nearest tenth, if necessary