well, each item is $1, and there are 4 of those, so all cost $4 then, what's the 5.5% of that?
[tex]\bf \begin{array}{|c|ll} \cline{1-1} \textit{a\% of b}\\ \cline{1-1} \\ \left( \cfrac{a}{100} \right)\cdot b \\\\ \cline{1-1} \end{array}~\hspace{5em}\stackrel{\textit{5.5\% of 4}}{\left( \cfrac{5.5}{100} \right)4}\implies 0.22[/tex]
