A deposit of 800 is made into a fund at time 0 . The fund pays interest at a nominal rate of discount, k compounded semiannually for the first three years. After that, interest is credited at a force of interest, t=t+11. At the end of five years, the accumulated value of the fund is 1,500 . Calculate k. 7.3% 7.6% 7.9% 8.2% 8.5%