Consider the following information on returns and probabilities:
State Probability X Z
Boom .25 15% 10%
Normal .60 10% 9%
Recession .15 5% 10%
What is the standard deviation for a portfolio with an investment of $6,000 in asset X and $4,000 in asset Z?
A) 6.10%
B) 8.15%
C) 1.85%
D) 3.00%
E) 5.18%