2. Dianne wants to know if the new learning modalities in the first semester affects the academic performance of senior high students. He took all the lists of all students in her school and selected every 6th name to be part of her study.

Case # 51173878 weighs 814 pounds; case # 51173981 weighs 803 pounds; case # 51174058 weighs 817 pounds; case 51174178 weighs 815 pounds; case # 51174248 weighs 817 pounds; case # 51174495 weighs 781 pounds; case # 51174577 weighs 828 pounds. what are the case #'s of the two cases that weigh the same amount?