To solve this question, we can use the simple interest formula.
Where A represents the end amount, P represents the investment, and r represents the rate. We have all of the values for the right side of the equation, then, we just need to plug them in the equation to get our desired value.
The interest is the amount added to our initial amount. Since we started with $2400 and ended with $2472, the interest is their difference.
The interest the account gained over 7 years is equal to $72.