Final answer:
To determine the largest annual fee that you'd be willing to pay for the cash back credit card, calculate the present value of the cash back payments using the formula P = A / (1 + r)^n, and compare it to the annual fee. For this scenario, the largest annual fee is approximately $309.41.
Step-by-step explanation:
To determine the largest annual fee that you'd be willing to pay in order to enroll in this credit card, we need to calculate the present value of the cash back payments and compare it to the cost of the annual fee. The present value can be calculated using the formula P = A / (1 + r)^n, where P is the present value, A is the future value (cash back payment), r is the monthly interest rate, and n is the number of months.
In this case, the future value (cash back payment) is 4% of the credit card bill each month, which is $40 ($1,000 * 4% = $40). The monthly interest rate can be calculated by dividing the annual interest rate (0.75%) by 12, which is approximately 0.0625%. Plugging these values into the formula, we get P = $40 / (1 + 0.0625%)^12, which is approximately $309.41. Therefore, the largest annual fee that you'd be willing to pay is $309.41.