Answer: 12 ft/s
Explanation:
We are told the following function models Spot's height at time
:
(1)
And we are asked to find Spot's average rate of ascent, this means its velocity
, which is calculated by:
(2)
Where:
is the height of Spot at time

is the height of Spot at time

is the final time
is the initial time
So, firstly we need to calculate
and
:
(3)
(4)
(5)
Substituting these values in (2):
(6)
Finally:
This is Spot's average rate of ascent