0.28 is roughly the same as 0.280, which has 3 significant digits (same as 0.205 has 3 significant digits). It's easier when we compare numbers having the same number of decimal places.
Comparing 0.280 to 0.205, we see that the hundredths place of 0.280 (which is 8) is greater than the hundredths place of 0.205 (which is 0). Thus 0.28 is greateer than 0.205.
The difference in elevation equals subtraction. In other words 39ft subtracted by 8ft equals 31ft. So New Orleans, Louisiana is 31ft ABOVE sea level compared to EL Centro, California.
