When 72? ,697.9 is rounded to the nearest ten thousand, the result is 720,000?

Not all the time, depending on the value of  the "?".

If ? is between 0 and 5 included, you are right because you round down. If it is between 6 and 9 included, you would get 730000.

The answers are 20,30,80,180,960,890,1230,4560. on the first row