There are 171 students in seventh grade. how much does money does mr. williams need to budget for the museum tickets and parking?

Here are the steps, you fill in the missing parts.
A. The given ratio is:
2 adults per 9 students or the fraction 2/9
Now put that fraction 2/9=x/171 in other words, how many adults (x) for 171 students?
can you cross multiply and get 9x=342
and solve for x?

How you have the number of students and the number of adults.

B. for food multiply $6 times the total number of people.

C. for tickets multiply 4.50 times the student number and
7.50 times the adult number.

D. for the bus parking fee multiply .04 times you total answer in part C.

Now add up the food, tickets, bus parking and I think you have what Mr. Williams has to budget.