4000 * 1.12 (12%) ^ 3 = $5619.71
Remember your percentage has to be expressed as 112% in a decimal, 1.12.
You can also do 4,000*1.12 = 4480 --> *1.12 --> 5017.6 --> *1.12 = 5619.71.
We do to the power of 3 as we will be doing the interest for 3 years.