Ariel deposited $23,000 into a fund at the beginning of every quarter for 13 years. She then stopped making deposits into the fund and allowed the investment to grow for 6 more years. The fund was growing at 6.24% compounded monthly.

a. What was the accumulated value of the fund at the end of year 13?

b. What was the accumulated value of the fund at the end of year 19?

c. What is the total amount of interest earned over the 19-year period?