The eleventh term in an infinite geometric sequence is 80.

Question

The fourteenth term in this series is 19.53125. What is the sum of this infinite series? Round your answer to the nearest 0.001

Answer 1

a₁₄ = a₁₁(r)³

19.53125 = 80(r³)

0.244140625 = r³

0.625 = r

 

Now determine a₁ and use S = a₁ / (1 - r).