Since the birth of her granddaughter, 18 years ago, Ariel has deposited $200 at the beginning of every month into a Registered Education Savings Plan (RESP). The interest rate on the plan was 4.50% compounded monthly for the first 9 years and 4.75% compounded monthly for the next 9 years.

a. What was the accumulated value of the RESP at the end of 9 years?

b. What was the accumulated value of the RESP at the end of 18 years?

c. What was the amount of interest earned over the 18-year period?