I dont know with the question your asking but I would maybe compare it with the 8 and 6 sorry I couldn't help much!
Answer:
a₄ = 1.25
Step-by-step explanation:
Given that,
First term of GP, a₁ = 10
The common ration of GP, r = 0.5
The nth term of the GP is given by :

So, the fourth term of the GP is 1.25.
Easy Engagement and Value