To calculate how much Shannon needs to pay monthly in order to pay off her $16,000 credit card debt with an 18% APR over 4 years, we can use the formula for the monthly payment on a loan with compound interest:

$M = \frac{P \times r(1 + r)^n}{(1 + r)^n - 1}$

Where:

• $M$ is the monthly payment.
• $P$ is the loan amount (or principal), which is $16,000.
• $r$ is the monthly interest rate, which is the annual interest rate (18%) divided by 12 months. So, $r = \frac{18\%}{12} = 0.015$.
• $n$ is the total number of payments, which is 4 years times 12 months per year, so $n = 4 \times 12 = 48$.

Now let's calculate the monthly payment $M$.Shannon will need to pay approximately $470 per month in order to pay off her $16,000 credit card debt over 4 years at an 18% APR.

Would you like more details on how this is calculated or have any other questions?

Here are 5 related questions to explore further:

1. How does the monthly payment change if the interest rate decreases to 12%?
2. What would happen if Shannon increases her repayment period to 5 years instead of 4?
3. How much total interest will Shannon pay over the 4 years?
4. What impact does paying more than the required $470 per month have on the total interest paid?
5. How would the payment change if the loan were compounded daily instead of monthly?

Tip: Paying more than the required monthly amount can significantly reduce the total interest paid over time!