MySQL Answer : SELECT ROUND(ABS(MIN(LAT_N) - MAX(LAT_N)) + ABS(MIN(LONG_W) - MAX(LONG_W)),4) FROM STATION

SELECT CAST(ROUND(ABS(MIN(LAT_N) - MAX(LAT_N)) + ABS(MIN(LONG_W) - MAX(LONG_W)), 4) AS DECIMAL(10,4)) FROM STATION

oracle

SELECT ROUND(ABS(MIN(LAT_N)-MAX(LAT_N)) + ABS(MIN(LONG_W)-MAX(LONG_W)), 4) FROM STATION MD;

SQL Server :

with cte as(
    select min(LAT_N) as a, min(LONG_W) b, max(LAT_N) as c, max(LONG_W) as d from station
), cte1 as(
        select (c-a) as p1, (d-b) as p2 from cte
    )
select cast(round(abs(p1+p2), 4) as decimal(10,4)) from cte1;

WITH CTE AS (SELECT MIN(LAT_N) AS a, MIN(LONG_W) AS b, MAX(LAT_N) AS c, max(LONG_W) AS d FROM STATION), CTE1 AS (SELECT (c-a) as p1, (d-b) as p2 from CTE) SELECT ROUND(ABS(p1+p2),4) FROM CTE1