# ?How do you find the sum of the infinite geometric series 4 + 3.2 + 2.56 + 2.048 + …?

##### 1 Answer

Jan 2, 2016

First find the common ratio (r) and make sure the series is convergent (0 ≤ r ≤ 1)

#### Explanation:

r =

r =

r = 0.8

The series has a sum of 20