Yellow star thistle is an invasive plant species; it is a big threat in the Santa Monica Mountains national recreation area. Ecologists have gathered data to model the spreading of the plant. Suppose the land area (in square miles) that has been overtaken by the thistle years after 2000 is given by \begin{align*} w(t) = 0.792t^3 - 4.196t^2 + 3.872t + 24.021. \end{align*} Compute the average rate of change of the land inhabited by yellow star thistle over the following intervals of years:
a) 2000 to 2005

b) 2005 to 2010

c) 2010 to 2015

Brainstorm: What does this suggest about the future of the park?

Hint: