Answer:
Approximately 71 .11 months
Step-by-step explanation:
This is a Future Value question. However we are solving for the Number of periods to determine how long it would take Joan to accumulate $3688.
Interest compounded monthly means Joan will be paid interest on her deposit on an annual basis prorated. she gets to earn interest on the accumulation of interest + principal monthly.
The formular for calculating Future Value is
FV = PV ( 1 + R )ⁿ
Our R which is the Rate(5%) will be adjusted to 12 months. =

However we need to solve for the N since we already have our FV. Therefore the revised formular is :

Continuing with the formular

Which is equals to 71.11 months approximately 6 years.