How much money does mr. williams need to budget for the museum tickets and parking?

I pretty sure the answer is $1086.80
okay so first you have the figure out how many students and teachers they're are gonna be. 
so if there's 171 students, and you need 2 adults for every 9 students then you need to divide 171 by 9 because it's 9 to a group so 1721 divided by 9 is 19. now you need to divide that by 2 because theres 19 groups of 9 and you need 2 adults for every 9, so 19 times 2 is 38. 
now that you have how many students and teachers are going you need to figure out how much is the total amount of tickets for everyone. if its 4.50 per student and 7.25 per teacher then you need to times $4.50 x 171 students and $7.25 x 38 adults. if you entered it right you should've gotten, $769.50 for the students and $275.50 for adults. add them both up. you should've gotten $1,045. 
okay so thats done with now the bus price. so if the bus price is 4% of the total price then you have to times .04 (4% in decimal) times $1045. the answer should be $41.80. so you $41.80 is the bus price now lastly you add that to the mount of the tickets. so last stop. $1045 + $41.80 = 1086.80 

So he needs to budget for the amount of $1086.80

I put the work down for you