Answer:
0.3400
Step-by-step explanation:
Total variance of security = (Standard deviation of security)^2 = (Beta)^2*(Standard deviation of security)^2 + (Standard deviation of error terms)^2
Total variance of security = (Standard deviation of security)^2 = (0.8)^2*(0.2)^2 + (0.3)^2
Total variance of security = (Standard deviation of security)^2 = 0.1156
Standard deviation of the rate of return on A = √0.1156
Standard deviation of the rate of return on A = 0.3400