Nearest thousand is 10000, which is nearer than 9000. 9704.8372 is 704.8372 away from 9000; but only 295.1628 away from 10000. The guide is usually the digit in the hundred position: if it's 5 or more then we go up to the next thousand (9 to 10 in this case), otherwise we just take the thousand digit as it is (9 in this case). 7, the hundred digit, is bigger than 5, so we take 10 thousand.
Nearest whole number is 9705, which is nearer than 9704, because the next digit 8 is bigger than 5 and the 4 in the ones position goes up to 5.
2 dec places is 9704.84, which is nearer than 9704.83.
3 sig figures is 9700. The 3 figures are 9, 7 and 0, because the zero is occupying a place separating it from the next digit 4, so it is significant. The 4 would make it 4 sig figures. The size of the number has to be preserved because, for example, 970 would not suggest the right number of thousands. Leading zeroes in whole numbers or mixed numbers are always discounted because they do not have any effect on the magnitude of the number.