Answer:
15 units per unit
Explanation:
From the graph we can easily tell that y increases from 0 to 15 as x increases from 2 to 3.
Thus, the average rate of change of f(x) on the interval [2, 3] is:
1 15 - 0 15 units
--------- * ----------- = -------------- = 15 units (rise) per unit (run).
3 - 2 1 1