Answer
The Naomi car had the highest number of miles per gallon with $25.2$ miles per gallon.
Work Step by Step
Jackie -> $\frac{364}{14.5} = 25.1$ miles per gallon
Maya -> $\frac{406}{16.3} = 24.9$ miles per gallon
Naomi -> $\frac{300}{11.9} = 25.2$ miles per gallon
The Naomi car had the highest number of miles per gallon with $25.2$ miles per gallon.