How to find the median? Arrange all similar data in order of size. If the number of data is odd, the middle data is the median of this group of data; If the number of data is even, the arithmetic mean of the middle two data is the median of this set of data.
Example: Find the median of this set of data 23, 29, 20, 32, 23, 2 1, 33, 25.
First, sort out this set of data (from small to large here) and get:
20、2 1、23、23、25、29、32、33
Because this set of data * * * consists of 8 data, n is an even number,
So according to the calculation method of the median, the median is (23+25)/2=24.
That is, the average of the fourth and fifth numbers.
The median is characterized by 1. Median is the representative value of all unit mark values determined by its position in all standard records, which is not affected by the maximum or minimum value of distribution sequence, thus improving the representativeness of weighted median to distribution sequence to some extent.
2. For some single series with discrete variables, when the distribution of time is skewed, the representativeness of the median will be affected.
3. tend to be in the middle of an ordered set of data.