A car's fuel efficiency, $F(s)$, in miles per gallon (MPG), is modeled by the function $F(s)=-0.01(s-50{)}^2+45$, where $s$ is the speed of the car in miles per hour (MPH) and $20\le s\le 80$. Which of the following is the best interpretation of the statement "$F(60)=44$" in this context?