5. Judy isn't sure whether a credit card using the average daily balance method, a credit card using the previous balance method, or a credit card using the
adjusted balance method is right for her. Regardless of the method used, Judy's
APR will be 26%. Her last 30-day billing cycle was typical for her, so she decided
to calculate the amount of interest charged by each method to compare them.
The opening balance of her last 30-day billing cycle was $930, and it remained
that amount for the first 10 days of the billing cycle. She then made a purchase
for $550, so her balance jumped to $1480, and it remained that amount for the
next 10 days. Judy then made a payment of $790, so her balance for the last 10
days of the billing cycle was $690.