Answer:
The annual interest rate for the account is 6%
Explanation:
Given : You put $5,000 in a simple interest account at a bank. You will earn $1,200 in just 4 years.
We have to calculate the rate of interest.
Using simple interest formula,

Where P is principal
r is rate of interest
t is time period.
Given Principal = $ 5000
t = 4
SI = 1200
Substitute, we have,

Simplify, for r, we have,
r = 6%
Thus, the annual interest rate for the account is 6%