a theater box office sold an average ( arithmetic mean ) of 68 tickets per staff member to a particular movie . among the daytime staff , the average number sold per member was 80 , and among the evening staff , the average number sold was 60 . if there are no other employees , what was the ratio of the number of daytime staff members to the number of evening staff members ?
"deviation from the mean for the daytime staff = 80 - 68 = 12 . deviation from the mean for the evening staff = 68 - 60 = 8 . thus , the ratio of the number of daytime staff members to the number of evening staff members is 8 : 12 = 2 : 3 . the answer is a ."
divide(subtract(68, 60), subtract(80, 68))