Answer
Rate of change$=0$.
The number of named hurricanes is staying constant from year to year (at 10).
Work Step by Step
To calculate the rate of change between two points $(a,f(a))$ and $(b,f(b))$, where $b\gt a$, we use the formula:
rate of change$=\frac{f(b)-f(a)}{b-a}$
We use the two points $(0,10)$ and $(3,10)$:
rate of change$=\frac{10-10}{3-0}=0$
Thus the number of named hurricanes is changing at a rate of 0 per year. In other words, the number of named hurricanes is staying constant from year to year (at 10).
