A baby crawls toward a toy. Its motion is shown on the following graph of horizontal position xxx vs. time ttt. Graph of x (in meters) vs. t (in seconds). The y-intercept is at 1 m, and the straight line also intersects (4, 2) and (8, 3). Graph of x (in meters) vs. t (in seconds). The y-intercept is at 1 m, and the straight line also intersects (4, 2) and (8, 3). What is the average speed of the baby between the times t=0\text{ s}t=0 st, equals, 0, start text, space, s, end text and t=4\text{ s}t=4 st, equals, 4, start text, space, s, end text?