In the context you've provided, the x-intercept of the graph represents the point where the hot air balloon reaches a vertical height of zero feet (meaning ground level) during its descent. Since the x-axis represents time in minutes (with values of 0, 10, 20, and 30) and the y-axis represents the height of the balloon in feet (ranging from 0 to 600), the x-intercept is the point where the line intersects the x-axis (y = 0).
To interpret this specific situation, if the line intersects the x-axis at, for example, x = 20, it indicates that the hot air balloon reaches ground level after 20 minutes of descent. This tells you how long it takes for the balloon to descend from its starting height to the ground.
In summary, the x-intercept provides valuable information about the duration of the descent until the balloon lands safely on the ground.