Business Mathematics Brief 12th Edition by Stanley Salzman ,Gary Clendenen, Charles Miller

Exercise 144

Find the rate in the following. Round to the nearest tenth of a percent. (See Example.)
Finding Rate Given Length of Loan
An exchange student from the United States living in Brazil deposits $5000 in U.S. currency in a Brazilian bank for 45 days. Find the rate if the interest is $75 in U.S. currency.
SOLUTION

Convert.12 to a percent to get 12%. Check the answer using the simple interest formula.
Solve using a calculator as follows. Notice that parentheses set off the denominator.