$6.(2$ points$)$ Stocks A and B have the following annual realized returns:

Year Stock A Stock B

$201320\%30\%$

$20145\%7\%$

$2015-5\%-3\%$

$20162\%-8\%$

$20177\%25\%$

a$)$ What are the average realized returns of the two stocks? $(0\mathrm{.}5$ point$)$

b$)$ What are the standard deviations of the returns of the two stocks? Don$$t use pre$-$set st$.$dev. functions

in your calculators$/$computers to get the answers. Please show your hand$-$calculation procedure. $(0\mathrm{.}5$

point$)$