The equation of the characteristic line of two stocks TCS and Bjaj Auto is estimated with the following results:

Stock The characteristic line

TCS Expected Return $=3\%+0\mathrm{.}7$ RNifty R$2=0\mathrm{.}20$

BAJA Expected Return $=-2\%+1\mathrm{.}2$ RNifty R$2=0\mathrm{.}12$

The SD of market index Nifty is estimated to be $20\%.$

Required:

$($i$)$ Calculate the standard deviation of each stock.

$($ii$)$ Break down the variance of each stock to the systematic and firm$-$specific components.