Two customers took out loans from a bank.

Jarrod took out a 5-year loan for $4,000 and paid 3.2% annual simple interest.
Harold took out a 7-year loan for $4,000 and paid 3.9% annual simple interest.
What is the difference between the amount of interest Jarrod and Harold paid for their loans??

To find the amount of interest paid by Jarrod, we multiply the loan amount ($4000) by the interest rate (3.2%) and the number of years (5).

Interest paid by Jarrod = $4000 * 0.032 * 5 = $640

To find the amount of interest paid by Harold, we multiply the loan amount ($4000) by the interest rate (3.9%) and the number of years (7).

Interest paid by Harold = $4000 * 0.039 * 7 = $1092

The difference in the amount of interest paid by Jarrod and Harold is $1092 - $640 = $<<1092-640=452>>452. Answer: \boxed{452}.