The P.E. teacher at Sunshine Middle School wants to know which sports are popular among students in her school. Since it would take so long to ask all of the students, she will survey a group of students. The school has 288 6th graders, 256 7th graders, and 280 8th graders. The P.E. teacher surveys 36 6th graders and 32 7th graders. How many 8th graders should she survey in order for the group to be a representative sample?