How long will it take $400,000 to grow to $750,000 at an annual rate of interest of 6.38% compounded semiannually? And if I add $500 each month for the next 5 years. Round the final answer to 3 decimal places.
a) 3.728 years
b) 4.156 years
c) 5.287 years
d) None of the above