first off, let's convert the mixed fraction to improper fraction, bearing in mind that a/b is really a decimal a ÷ b, and (a ÷ b ) * 100 is the percent format.
[tex]\bf \stackrel{mixed}{3\frac{5}{8}}\implies \cfrac{3\cdot 8+5}{8}\implies \stackrel{improper}{\cfrac{29}{8}} \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ 29\div 8\implies \stackrel{decimal}{3.625}~\hfill 3.625\cdot 100\implies \stackrel{percent}{362.5\%}[/tex]
