A geometric sequence refers to a sequence where to get from one term to another you need to multiply by the same number each time.
On this case are given the numbers 4,16,64,256 as part of the sequence.
From 4 to 16 is multiply by 4.
From 16 to 64 is multiply by 4.
From 64 to 256 is multiply by 4.
After the previous reasoning, you can conclude that the common factor of the geometric sequence is 4; meaning that it is true, the given sequence is geometric.
