Investment 1 has an expected return of 11.7% with a standard deviation of 7.4% . Investment 2 has an expected return of 9.1% with a standard deviation of 18.5% . These investments have a correlation of 0.46 . Suppose you have a portfolio that is composed of 1 ( 45% ) and 2 ( 55% ) , what is the standard deviation of your portfolio's returns? .