To find the median, we order all the values from least to greatest and pick out the middle one:
6, 8, 9, 18, 18, 18
Since there’s an even amount of numbers, there the real median can be found by taking the mean of the two values:
(9 + 18) / 2 = 13.5
To find the mean of the whole data set, we add all the numbers together and divide by the amount of numbers there are:
(6 + 8 + 9 + 18 + 18 + 18) / 6
= 77 / 6
= 12.8 (rounded to the tenth)
So the MEDIAN is 13.5 hours, and the MEAN is 12.8 hours! :)