Question 1000556
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The sequence 100,120,160,220 . . . is NOT a geometric progression.


Because the ratio of the next term to the current term is not a constant value.


Indeed, 


{{{120/100}}} = 1.2,


{{{160/120}}} = {{{4/3}}} = 1.33(3) =/= 1.2.


Read the lesson on geometric progression in this site <A HREF=http://www.algebra.com/algebra/homework/Sequences-and-series/Geometric-progressions.lesson>Geometric progressions</A>.