Since we know that the graph of our quadratic function has x-intercepts at (6,0) and (18,0), and are the zeroes of our quadratic. To find our quadratic we are going to factor each zero backwards and multiply them:
Now that we have our quadratic function, we are going to use the average formula:
is the function evaluated at the <span>9th month </span> is the function evaluated at the 3rd month
We can conclude that the closest approximate average rate of change for Edna's profits from the 3rd month to the 9th month is: <span>B. −11.63 dollars per month.</span>