Final answer:
To find out how much additional money Mrs. Stevens will need to add after three years to her investment to make her balance $18,000, we need to calculate the future value of her initial deposit and subtract it from $18,000.
Step-by-step explanation:
To find out how much additional money Mrs. Stevens will need to add after three years to her investment to make her balance $18,000, we need to calculate the future value of her initial deposit and then subtract it from $18,000.
Step 1: Convert the annual interest rate to a quarterly rate: 4% / 4 = 1%
Step 2: Convert the number of years to the number of quarters: 3 years * 4 = 12 quarters
Step 3: Calculate the future value of the initial deposit: Future value = $9500 * (1 + 0.01)^12 = $10,704.84
Step 4: Calculate the additional money needed: Additional money = $18,000 - $10,704.84 = $7295.16
Therefore, Mrs. Stevens will need to add $7295.16 after three years to her investment to make her balance $18,000.