Answer :
We are given a mass in grams and are asked to convert it to milligrams. Therefore, we do a rule of three as follows:
[tex]\begin{gathered} 1g\text{ --> }1000mg \\ 12.3g\text{ --> }xmg \end{gathered}[/tex]That rule of three leaves us with this equation:
[tex]x=\frac{12.3(1000)}{1}\text{ --> }x=12300mg[/tex]Therefore, we conclude that 12.3 grams of fat are 12300mg of fat