The total amount is $967.5
The cost for renting the bus is, $450
The cost for food is, $28.75 per person.
Let x be the number of people the marching band could bring, then,
[tex]967.5=450+(28.75)x[/tex]Thus, it is the required equation. On solving we have,
[tex]\begin{gathered} 967.5-450=(28.75)x \\ 517.5=(28.75)x \\ x=\frac{517.5}{28.75}\rightarrow x=18 \\ \end{gathered}[/tex]Thus, the number of persons is 18.