It is given in the question that,
A ball is thrown upward from the top of a building. The function below shows the height of the ball in relation to sea level, f(t), in feet, at different times, t, in seconds:
[tex]f(t) = −16t^2 + 32t + 384[/tex]
At t=4seconds,
we will get
[tex]f(4) = -16(4)^2+32(4) +384 = $256[/tex]
At t=6 seconds, we will get
[tex]f(6)= -16(6)^2 +32(6)+384 =0[/tex]
THerefore, average rate of change is
[tex]\frac{f(6)-f(4)}{6-4} = \frac{0-256}{2-0} = -128feet/second[/tex]
And that's the required answer .
