Four years ago, Texaco issued $5 million worth of debenture bonds having a bond interest rate of 10% per year, payable
semiannually. Market interest rates dropped, and the company called the bonds (i.e., paid them off in advance) at a 10% premium on the face value (i.e., paid $ 5.5 million to retire the bonds). What semiannual rate of return did an investor
make if he purchased one $5000 bond at face value 4 years ago and held it until it was called 4 years later?