Answer:
effective annual rate = 9.77%
monthly rate = 0.78%
Explanation:
we can solve this by using a financial calculator or an excel spreadsheet:
our initial outlay = -25,995
then we have 72 cash flows = 474
I prefer to use excel, since all you need to do is use the IRR formula to determine the interest rate at which the NPV = 0. The interest rate at which NPV = 0 is the effective monthly interest rate. IRR = 0.78% monthly
In order to determine the effective annual rate:
EAR = (1 + 0.0078)¹² - 1 = 1.0977 - 1 = 0.0977 = 9.77%