\(\bf {{ a}}\%\ of\ b \implies \cfrac{{{ a}}}{100}\cdot b\implies {{ a}}\div 100\cdot b\qquad thus\\\\
-----------------------------\\\\
{{ 4\frac{1}{5}}}\%\ of\ 63.78 \implies \cfrac{{{ 4\frac{1}{5}}}}{100}\cdot 63.78\implies {{ 4\frac{1}{5}}}\div 100\cdot 63.78\)
you tell us, what would you end up multiplying 63.78 there, to get the 4 1/5% of it?
