We are given, a certain food has a gluten ratio of
.
We need to convert milligrams per liter into micro-grams per milliliter.
1 mg = 1000 micro-grams.
And 1 L = 1000 milliliter.
Substituting 1 mg = 1000 micro-grams and 1 L = 1000 milliliter, we get
![13 (1000 \ micro-grams)/(1000 \ milliliter) = 13 (micro-grams)/(milliliter)](https://img.qammunity.org/2019/formulas/mathematics/high-school/gk41npsnmigrtucn1jeb0ia5zb7d8roa5j.png)
= 13 µg/mL