2.6 feet per step is the answer
You always get from one term to the next by adding 6:




So, the rule is "add 6"
Assuming the cylinder is closed at both ends
Surface area = 2 pi r^2 + 2 pi r h = 108
now h = r/2 so we have:-
2pi r^2 + pi r^2= 108
3 pi r^2 = 108
r^2 = 11.459
r = 3.385
so the height h = 1.693 m to nearest thousandth