Question

if the fourth term of a geometric sequence of positive numbers is 200 and the eighth term is 800, what is the sixth term?

Answer 1

Answer:

400

Step-by-step explanation:

The fourth term = a*r^3=200

The eights term = a*r^7=800

The sixth term = a*r^5= a*r^3*r^2=200*r^2

ar^7/ar^3=r^4=(r^2)^2=800/200

(r^2)^2=4

r^2=2

So the sixth term = 200*2=400