$($j$)$ Find each investment's monthly returns in excess of the risk$-$free return. The risk$-$free return is

$0\mathrm{.}137\%$ per month $(1\mathrm{.}64\%$ per year$).($j$)$ Find each investment's monthly returns in excess of the risk$-$free return. The risk$-$free return is

$0\mathrm{.}137\%$ per month $(1\mathrm{.}64\%$ per year$).$