Final answer:
To find the interest rate for a simple interest problem, we can use the formula: Interest = Principal x Rate x Time. By plugging in the given values, we can solve for the rate. In this case, the interest rate is approximately 8.1%.
Step-by-step explanation:
To find the interest rate, we can use the formula for simple interest: Interest = Principal x Rate x Time.
In this case, the principal is $528 and the time is 15 years.
The interest is $1,137 - $528 = $609. Plugging these values into the formula, we get: $609 = $528 x Rate x 15.
Dividing both sides by $528 x 15 gives us the rate: Rate = $609 / ($528 x 15).
Calculating this expression gives us a rate of approximately 0.081 or 8.1%.
Therefore, the interest rate is 8.1%.