Suppose Wesley$$ Publishing's stock has a volatility of $45\%$

$,$

while Addison$$ Printing's stock has a volatility of $25\%$

$.$

If the correlation between these stocks is $75\%$

$,$

what is the volatility of the following portfolios of Addison and$$ Wesley:

a$.100\%$

Addison

b$.75\%$

Addison and $25\%$

Wesley

c$.50\%$

Addison and $50\%$

Wesley