Answer:
Yes, the number of days are proportional to the number of liters of water the elephant drinks.
Step-by-step explanation:
1 day: 225L 2 days: 450L 3 days: 675L 4 days: 900L
There is a proportional pattern to it.

Multiplication by 10ⁿ → move decimal n places to the right.
Multiplication by 10⁻ⁿ → move decimal n places to the left.
For n ∈ N