Question 1022945
For a(x) = 680*4.3^x you can see that when x = 0, a(0) = 680.
Thus 680 is the initial amount.
The 4.3 is the growth factor...when x = 1, a(1) is 680*4.3.
When x = 2, a(2) = 680*4.3^2 and so on...