1192.64-819.73 is 372.91
so... if we take 1192.64 to be the 100%, how much is 372.91 in percentage then?
[tex]\bf \begin{array}{ccll}
amount&\%\\
\text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\
1192.64&100\\
372.91&p
\end{array}\implies \cfrac{1192.64}{372.91}=\cfrac{100}{p}\implies p=\cfrac{372.91\cdot 100}{1192.64}[/tex]
