Dorothy lacks cash to pay for a $$840\mathrm{.}00$ dishwasher. She could buy it from the store on credit by making $12$ monthly

payments of $$71\mathrm{.}52.$ The total cost would then be $$858\mathrm{.}24.$ Instead, Dorothy decides to deposit $$70\mathrm{.}00$ a month in the bank

until she has saved enough money to pay cash for the dishwasher. One year later,'she has saved $$882\mathrm{.}00-$$$840\mathrm{.}00$ in

deposits plus interest. When she goes back to the store, she finds the dishwasher now costs $$886\mathrm{.}20.$ Its price has gone up

$5\mathrm{.}50$ percent.

Was postponing her purchase a good trade$-$off for Dorothy?