75th percentile.
order them from lowest to highest
12, 18, 34, 55, 59, 68, 80, 80
0 percentile is 12
100 percentile is 80
50 percentile is 57: average of 55 and 59
25 percentile is 26: average of 18 and 34
75 percentile is 74: average of 68 and 80
Answer is 74
