a. Invest $400.00 and receive $813.71 in 12 years. b. Invest $2,800.00 and receive $11,249.05 in 16 years. c. Invest $30,186.95 and receive $120,000.00 in 22 years. d. Invest $31,536.54 and receive $1,500,000.00 in 45 years. a. What annual rate of return will Keiko earn if she invests $400.00 today and receives $813.71 in 12 years? % (Round to two decimal places.)