The arithmetic average return on your portfolio for the past five years is 9.3 percent. You earned -7.4 percent, 171 percent, 6.3 percent, and 11.8 percent for four of those five years. What rate of return did you earn in the fifth year? Multiple Choice O 16.0% O 13.2% O 18.7% O 17.5% O 19.6%