Answer:
12%
Explanation:
We are trying to find the percent increase from the original cost to the payment plan cost. To do that, we need to first figure out how much the payment plan would cost in total.
Lets solve for the cost of the payment plan:
$120 + $89.30(8) = $834.40
Next, use the percent increase formula as shown below:
![x=(New-Original)/(Original) (100)](https://img.qammunity.org/2021/formulas/mathematics/high-school/24j3ny1jyb7ebpyhqr7ir8l7phqrkl3lzb.png)
Plug in the values:
1)
![x=(834.40-745)/(745) (100)](https://img.qammunity.org/2021/formulas/mathematics/high-school/3xxg6tfbed24og54de4a6kaubxu0emz8pj.png)
2)
![x=.12(100)](https://img.qammunity.org/2021/formulas/mathematics/high-school/ox836ykubg21ek452dw96g78hf0mm81uzm.png)
3)
![x=12](https://img.qammunity.org/2021/formulas/mathematics/middle-school/kzh72we7ptn8hlgavxhsl5e208kjtiramm.png)
Our answer is 12%.