4 ounce bottle of medicine contains 20 doses how many doses are in a 13 ounce of all of the same medicine
\(\bf \begin{array}{ccllll}
ounces&doses\\
\textendash\textendash\textendash\textendash\textendash\textendash&\textendash\textendash\textendash\textendash\textendash\textendash\\
4&20\\
13&x
\end{array}\implies \cfrac{4}{13}=\cfrac{20}{x}\)
solve for "x"