so.. 2.86 - 2.79 is the amount in decrease or 0.07
so.. if we take 2.86 as the 100%, how much is 0.07 of that in percentage?
well [tex]\bf \begin{array}{ccllll}
amount&\%\\
\textendash\textendash\textendash\textendash\textendash\textendash&\textendash\textendash\textendash\textendash\textendash\textendash\\
2.86&100\\
0.07&x
\end{array}\implies \cfrac{2.86}{0.07}=\cfrac{100}{x}[/tex]
solve for "x"
