Median value is the value that “splits” you set of values in half
Imagine you have following values: First, you need to sort them: And the median value would be .
If you have even amount of values: Then median value will be Mean value of 2 values that are in the center:
Finding median is basically answering question: What is the number that splits observations into two halves: the first one is less than this number, another half is greater?
Median shows better picture than mean in cases when there are outliers in data. Popular example is income statistics. If ask 5 people what is their monthly income and you receive following answers: 2000, 1900, $50000.
Mean value will be: 2000
“On average people make 2000 a month”