Final answer:
Gavin confused the simple division of the annual rate by the number of quarters with the correct method of determining the equivalent quarterly rate. The correct quarterly interest rate equivalent to an annual rate of 9% compounded annually is approximately 2.206%, determined by the formula (1 + 0.09)^(1/4) - 1.
Step-by-step explanation:
Gavin is not correct about the equivalent quarterly interest rate. If an account is compounded annually at a 9% rate, the equivalent quarterly interest rate is found using the formula for converting annual interest rates to other compounding periods:
(1 + annual rate)^1/n - 1, where n is the number of compounding periods per year.
For quarterly compounding, n = 4. So the calculation is (1 + 0.09)^(1/4) - 1, which is approximately 2.206% per quarter, not 2.25%.
Here is the detailed calculation:
(1 + 0.09)^(1/4) = (1.09)^(0.25)
(1.09)^(0.25) ≈ 1.02206
1.02206 - 1 = 0.02206
0.02206 × 100 = 2.206%