Q. An investor puts $15,000 into each of four stocks, labeled A, B, C, and D. The table shown below contains the means and standard deviations of the annual returns of these four stocks.
stock Mean annual rate Standard Deviation of Annual return
A 0.15 0.05
B 0.18 0.07
C 0.14 0.03
D 0.17 0.06
Assume that the returns of these stocks are independent of each other. Find the mean and standard deviation of the total amount that this investor earns in one year from these four investments.