namely, how many times does 4 and 1/2 go into $27? well, is just their quotient.
let's change first the mixed fraction to "improper", and proceed from there,
[tex]\bf \stackrel{mixed}{4\frac{1}{2}}\implies \cfrac{4\cdot 2+1}{2}\implies \stackrel{improper}{\cfrac{9}{2}}\\\\
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\cfrac{\quad 27 \quad }{\frac{9}{2}}\implies \cfrac{\quad \frac{27}{1} \quad }{\frac{9}{2}}\implies \cfrac{27}{1}\cdot \cfrac{2}{9}\implies \cfrac{54}{9}\implies 6~\frac{\$}{kg}[/tex]
