If you look through the data, it is clear that 46, 59, 63, 68, 72, 76, 78, 85, and 89 are all less than 90. There are <em>9 elements total </em>that are less than 90.
For percentages, you take the number you have and divide by the total. Since we know that there are 15 students, we can do 9 / 15. This gives us 0.6 which is 60%
