Question

图中显示了一支越野队训练跑的结果。哪位学生的平均速度最大？

The results of a cross-country team's training run are graphed below. Which student has the greatest average speed?

$\text{Angela}$

$\text{Briana}$

$\text{Carla}$

$\text{Debra}$

$\text{Evelyn}$

平均速度是距离除以时间，也就是从原点到该点连线的斜率。

Evelyn 的斜率最大，因此她的平均速度最大。

所以正确答案是 E。

Average speed is distance over time, which is given by the slope of the line through the point and the origin.

Evelyn has the steepest slope, telling us that she had the greatest average speed.

Thus, E is the correct answer.