Question

Hey I just need someone to check my answer on this. I'll fan and medal :)

The function below shows the number of car owners f(t), in thousands, in a city in different years t:

f(t) = 0.25t^2 - 0.5t + 3.5

The average rate of change of f(t) from t = 2 to t = 6 is ______ thousand owners per year.

I think the average rate of change is 2.38?

Answer 1

How did you get 2.38?

Answer 2

Well, I plugged in 2 for every t in the equation, and then I plugged in 6 for every t in the equation. I solved them, took the difference and divided it by the number of years between 2 and 6, so, 4.

Answer 3

So the first equation was f(2) = 3.5 and the second equation was f(6) = 9.5.

Answer 4

Yes, those are correct.

Answer 5

So the average rate of change IS 2.38??

Answer 6

9.5 - 3.5 would give you the average rate of change.

Answer 7

Yes, but they are asking the average rate of change, in thousands, PER YEAR. I think that is just overall change. :)

Answer 8

But 9.5 - 3.5 = 6 and then you divide 6 by the number of years which would be 4 so 6/4 = 1.5. I think that 2.38 is wrong...

Answer 9

It's asking in thousand of people, the answer does not have to be in the thousands place.

Answer 10

Ok I'm not sure what you mean but my question is asking the average rate of change per year, not overall. :D

Answer 11

Average rate of change from t :2 to t:6, so the change in those intervals, that would be the difference between 9.5 and 3.5.

Answer 12

Maybe you could read the question again just to make sure? I still think they are asking for it per year... :)

Answer 13

I think that I'll just go with 1.5. Thanks though. Ttyl :)