An investor forms a portfolio of two stocks, Alpha and Beta. Information regarding the two stocks is shown below:

Stock Expected Return Standard Deviation

Alpha $8\%30\%$

Bravo $9\%40\%$

The correlation between returns on Alpha and Bravo is $0\mathrm{.}40.$ The investor will put $40\%$ of her wealth in Alpha and the $60\%$ of her wealth in Bravo. What is the standard deviation of the investor$$s portfolio?