Glencoe Algebra 2, Chapter 2, 2.4, Section 2.4, Problem 67

The median of a set of numbers is the value for which half the numbers are larger and half are smaller. If there are two middle numbers, the median is the arithmetic mean of the two middle numbers.
To find the median, first list the numbers from least to greatest.
[2.5, 7.8, 5.5, 2.3, 6.2, 7.8] [2.3 ,2.5 ,5.5 ,6.2 ,7.8,7.8]
Next, find the exact middle. In this case, there are two numbers (5.5 and 6.2) in the middle. Therefore, find the mean (or average) of these two numbers.
To find the mean, add the two numbers and divide by 2.
(5.5+6.2)/2=5.85
The median of this data set is 5.85. Exactly half the numbers in the data set are larger than 5.85 and exactly half the numbers in set are smaller than 5.85.