The standard deviation of the market$-$index portfolio is $45\%.$ Stock A has a beta of $1\mathrm{.}20$ and a residual standard deviation of $55\%.$

Required:

a$.$ Calculate the total variance for an increase of $0\mathrm{.}20$ in its beta. $($Do not round intermediate calculations.$)$

b$.$ Calculate the total variance for an increase of $3$ percentage points in its residual standard deviation. $($Do not round intermediate calculations.$)$

Total variance