## Precalculus (6th Edition)

The average rate of change in the interval $[0, 4]$ is $0\%$ The percent of pay raise is constant at $3\%$ per month.
The graph is from $x=0$ to $x=4$ so the interval is $[0, 4]$. RECALL: The average rate of change in the interval $[a, b]$ is given by the formula: average rate of change = $\dfrac{f(b)-f(a)}{b-a}$ The given graph has $f(0) = 3$ and $f(4) = 3$. Thus, the average rate of change in the interval $[0, 4]$ is: $=\dfrac{f(4)-f(0)}{4-0} \\=\dfrac{3-3}{4} \\=\dfrac{0}{4} \\=0$ Therefore, the percent of pay raise is constant at $3\%$ per month.