Suppose that the index model for stocks A and B is estimated from excess returns with the following results:

RA $=1\mathrm{.}5\%+0\mathrm{.}55$RM $+$ eA

RB $=-1\mathrm{.}4\%+0\mathrm{.}6$RM $+$ eB

$\backslash$sigma M $=18\%$; R$$squareA $=0\mathrm{.}25$; R$$squareB $=0\mathrm{.}16$

What is the standard deviation of each stock?