To order the stars from least to greatest volume, we need to arrange the numbers from smallest to largest.
Here are the numbers in order:
2.7 x 1024 km3
1.3 x 1024 km3
3.4 x 1015 km3
6.9 x 1015 km3
So, the order of the stars from least to greatest volume is:
2.7 x 1024 km3
1.3 x 1024 km3
3.4 x 1015 km3
6.9 x 1015 km3
Hope this helps you, have a nice day/night!