Answer
No, the provided statement does not make any sense.
Work Step by Step
Here, the line is not straight, but the slope can be analyzed by considering any two points on a secant line.
For example:
The value of the number of discharges for the year $1994$ is $617$.
The value of the number of discharges for the year $1998$ is $1163$.
Substitute the values $\left( {{x}_{2}},{{x}_{1}} \right)=\left( 1998,1994 \right)$and $\left( f\left( {{x}_{2}} \right),f\left( {{x}_{1}} \right) \right)=\left( 1163,617 \right)$ to get the rate of change:
$\begin{align}
& m=\frac{\left( f\left( {{x}_{2}} \right)-f\left( {{x}_{1}} \right) \right)}{\left( {{x}_{2}}-{{x}_{1}} \right)} \\
& m=\frac{1163-617}{1998-1994} \\
& m=136.5 \\
& m\approx 137 \\
\end{align}$
Therefore, it is not necessary to analyze the slope only for straight lines; the slope can be used for non-straight lines also. So, the statement does not make any sense.
