Question

What is the avarage rate from x=1 to x=3

Answer 1

It depends on the line or parabola that you are talking about, more information would be needed to answer this correctly.

Answer 2

I'm really not allowed to follow a link outside of Brainly. Don't make a habit of it. I take it we are still on y = 8*(1.2)^x

Rate of change = (y2 - y1)/(x2 - x1) = (13.824 - 9.6) / 3 - 1

Rate of change = (4.224) / 2 = 2.112