An investor puts $10,000 in each of 4 stocks, labeled A, B, C and D. The following are the means and the standard deviations of the annual returns of these four stocks. Assuming that the returns of these four stocks are independent of each other, determine the mean and the standard deviation of total amount that this investor in one year from these four investments.
Stock

Mean annual return

Stdev. of annual return

A

0.13

0.04

B

0.16

0.06

C

0.12

0.02

D

0.15

0.05
