Joe plans to retire in 15 years. He currently has saved up $100,000, and he believes he will need $1,000,000 at retirement. What annual interest rate must Joe earn to reach his goal, assuming he does not save any additional funds between now and retirement?
a. 6.00%
b. 60.00%
c. 10.00%
d. 16.59%
e 0.67%