Given that Amistad deposited $2,163.27 in a savings account that earns 3.9% simple interest.
That means we need to use Simple interest formula to find the Amistad's account balance in nine months.
Simple interest formula is
A=P(1+RT)
Where P= principal amount = $2163.27
R= rate of interest = 3.9%= 0.039
T= time in years = 9 months = 9/12 years = 0.75
Now plug these values into above formula:
A=2163.27(1+0.039* 0.75)
A=2163.27(1+0.02925)
A=2163.27(1.02925)
A=2226.5456475
Hence Amistad's account balance in nine months will be approx $2226.55
