It was really interesting to calculate Median of entries in the SQL database.
Refer the link about [Median|https://en.wikipedia.org/wiki/Median]
A median is defined as a number separating the higher half of a data set from the lower half. Query the median of the Northern Latitudes (LAT_N) from STATION and round your answer to 4 decimal places.
SET @index := -1; SELECT ROUND(AVG(s.LAT_N), 4) FROM (SELECT @index:=@index + 1 AS index, LAT_N FROM STATION ORDER BY LAT_N) AS s WHERE s.index IN (FLOOR(@index / 2) , CEIL(@index / 2));