MS SQL Server

SELECT
    CAST(SQRT(POWER(MIN(LAT_N) - MAX(LAT_N),2) + POWER(MIN(LONG_W) - MAX(LONG_W),2)) AS DEC(20,4))
FROM STATION

SELECT ROUND(SQRT(POWER((MIN(LAT_N) - MAX(LAT_N)), 2) + POWER((MIN(LONG_W) - MAX(LONG_W)), 2)), 4) FROM STATION;

I think the confusing problem about the values of (a,b) and (c,d) when saying the values corresponding to min, max of lat_n and min, max of long_w. Readers will easily understand it as a = min(lat_n), b = max(lat_n), c = min(long_w), d = max(long_w). While to get the correct result for this problem, we need a = min(lat_n), b = min(long_w), c = max(lat_n), d = max(long_w)

SELECT ROUND(SQRT( POWER(MAX(LAT_N)-MIN(LAT_N),2) + POWER(MAX(LONG_W)-MIN(LONG_W),2) ),4) FROM STATION;

Using MySQL:-

SELECT ROUND(SQRT(POW(MAX(LAT_N) - MIN(LAT_N), 2) + POW(MAX(LONG_W) - MIN(LONG_W), 2)), 4) FROM STATION;