Answer
Geometric, the common ratio is $\frac{3}{4}$
Work Step by Step
You have the sequence:128,96,72,54. Find the common ratio by using the formula: R=$\frac{a2}{a1}$,R=$\frac{a4}{a3}$.Plug in the values to get the ratios.
r=$\frac{96}{128}$=$\frac{3}{4}$
r=$\frac{54}{72}$=$\frac{3}{4}$
There is a common ratio, r=$\frac{3}{4}$. So the sequence is geometric.
