Answer: The volume of the bigger pentagonal prism will be 64 times the volume of the smaller pentagonal prism.
Step-by-step explanation: Given that a pentagonal prism has dimensions that are four times the dimensions of a similar pentagonal prism.
We know that
the volume of a pentagonal prism with base edge a units and height h units is given by

If a' and h' are the base edge and height of the similar pentagonal prism, then according to the given information, we have

So, the volume of the similar bigger prism will be

Thus, the volume of the bigger pentagonal prism will be 64 times the volume of the smaller pentagonal prism.