Question

What is the fourth term in a geometric sequence for a1=10 and r=0.5

Answer 1

For the answer to the question above, I'll show the solution to my answer below.

a2 = a1 * r
a2 = 10 * .5 = 5
a3 = a2 * r
a3 = 5 * .5 = 2.5
a4 = a3 * r
a4 = 2.5 * .5 = 1.25
So the answer to your problem is
1.25

I hope my answer helped you.