Given that :-
Geometric sequence → -320,80,-20,5
To find :-
Common ratio .
Solution :-
Common ratio = ar/a
→ Here a = -320
→ ar = 80
→ Common ratio = 80/-320
Let's check it →
Taking a = 80 and ar = -20
→ Common ratio = -20/80
So common ratio will be -1/4