To compare the amounts saved by each friend:
- Sami: $41.79
- Charlotte: $38.91
- Celeste: $41.68
Now, let's order them from least to greatest:
- Charlotte: $38.91 (least)
- Celeste: $41.68
- Sami: $41.79 (greatest)
So the correct order from least amount saved to greatest is:
Charlotte, Celeste, Sami.