To determine the interest rate required for Maria's investment to double, we can use the formula for simple interest and solve for the rate.
To determine the interest rate required for Maria's investment to double in value in 18 years, we can use the formula for simple interest:
Simple Interest = Principal × Interest Rate × Time
Since Maria wants her investment to double, we can set up the equation as:
$8800 × Interest Rate × 18 = $8800 × 2
Cancelling out $8800 on both sides, we have:
Interest Rate × 18 = 2
Dividing both sides by 18, we find:
Interest Rate = 2 / 18 = 0.1111
Since we need to round our answer to the nearest tenth of a percent, the interest rate needed is approximately 11.1%.