Answer:
Option (3)
Step-by-step explanation:
For a geometric progression,
[tex]a,ar,ar^{2},ar^3.........a(r)^{n-1},a(r)^n[/tex]
First term of the progression = a
Common ratio of each successive term to the previous term = r
Recursive formula for geometric progression will be,
[tex]a_1=a[/tex]
And [tex]a_{n}=a_{n-1}(r)[/tex]
Following this rule for the G.P. given in the question,
[tex]a_1=4[/tex]
[tex]a_n=-1.5a_{n-1}[/tex]
Therefore, from the recursive formula,
Common ration 'r' = -(1.5)
Option (3) will be the correct option.
