Eudora transferred a balance of $6400 to a new credit card at the beginning
of the year. the card offered an introductory apr of 7.8% for the first 3
months and a standard apr of 26.5% thereafter. if the card compounds
interest monthly, what will eudora's balance be at the end of the year?
(assume that eudora will make no payments or new purchases during the
year, and ignore any possible late payment fees.)