Given:
Amount = $3000
Interest rate = 18% per year
A = 3000(1.18)^t
To find:

Step-by-step solution:
We will now the value in the given expression:
![\begin{gathered} =(A(12)-A(6))/(12-6) \\ \\ =(3000[(1.18)^(12)-(1.18)^6])/(6) \\ \\ =500[7.28-2.69] \\ \\ =500*4.59 \\ \\ =2294.02 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/mxm0la5vdxomiluzenkveb3cl2gyldg5oo.png)
From the above calculation, we can say that the average total amount between t = 6 years to t = 12 years is 2294.02
Thus we can say that Option A is the correct answer.