For the past 13 years, Ms. Perrault has contributed $2000 at the beginning of every six months

Question:

For the past 13 years, Ms. Perrault has contributed $2000 at the beginning of every six months to a mutual fund. If the mutual fund statement at the end of the 13 years reports that her fund units are worth a total of $91,477, what has been the semiannually compounded nominal rate and the effective rate of return on her investments over the 13 years?