5.2.1 Beta endorphin concentration (collapsed runners)
The final column of Table 4 contains the blood plasma β endorphin concentrations for eleven runners who collapsed towards the end of the Great North Run. The observations are already sorted. They are as follows.
Eleven is an odd number, so the middle value of the data set is the sixth value (five either side). So, in this case, the sample median is 110 pmol/l.