At a restaurant, if a party has eight or more people, the gratuity is automatically added to the bill. If $x$ is the cost of the meal, then the total bill $C(x)$ with an $18 \%$ gratuity and a $6 \%$ sales tax is given by: $C(x)=x+$ $0.06 x+0.18 x$. Evaluate $C(225)$ and interpret the meaning in the context of this problem.