well, if we take that 28.2lbs is the 100%,
then it went down to 15.5lbs,
how much, in percentage is 15.5?
well [tex]\bf \begin{array}{ccllll}
amount&\%\\
\textendash\textendash\textendash\textendash\textendash\textendash&\textendash\textendash\textendash\textendash\textendash\textendash\\
28.2&100\\
15.5&x
\end{array}\implies \cfrac{28.2}{15.5}=\cfrac{100}{x}[/tex]
solve for "x"
