The standard deviation of the market$-$index portfolio is $20\%.$ Stock A has a beta of $2\mathrm{.}50$ and a residual standard deviation of $30\%.$

Required:

a$.$ Calculate the total variance for an increase of $0\mathrm{.}25$ in its beta. $($Do not round intermediate calculations.$)$

Total variance

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

Total vari