The width is basically the diameter:
Given
Diameter = 5.5 cm
So Radius = [tex] \frac{d}{2} [/tex] = [tex] \frac{5.5}{2} [/tex] = 2.75 cm
Height of cylinder = 12.5 cm
Formula of the volume of a cylinder
V = Area of base × height of prism
= [tex] \pi [/tex]r² × h
=(2.75)² ([tex] \pi [/tex]) × 12.5
=7.5625[tex] \pi [/tex] × 12.5
≈ 296.83 cm³