Problem:
A portfolio has 40% of its value in IBM shares and the rest in Microsoft (MSFT). The volatility of IBM and MSFT are 40% and 30%, respectively, and the correlation between IBM and MSFT is -0.3.
Required:
Question: What is the standard deviation of the portfolio?
A. 19.95%
B. 18.65%
C. 22.17%
D. 20.18%
Note: Show all workings.