The average rate to lower the ball per minute is 100/3
Explanation:Given the ordered pairs (10, 400) and (40, 1400)
The average rate of change is given as:
[tex]\begin{gathered} \frac{y_2-y_1}{x_2-x_1} \\ \\ \text{where} \\ x_1=10 \\ y_1=400 \\ x_2=40 \\ y_2=1400 \end{gathered}[/tex]Using these parameters, we have:
[tex]\begin{gathered} \frac{1400-400}{40-10} \\ \\ =\frac{1000}{30}=\frac{100}{3} \end{gathered}[/tex]