Answer
$4$
Work Step by Step
The general formula to find the sum of an infinite Geometric series is given as:
$ S_{n}=\dfrac{a_1}{(1-r)}$
and $ r=\dfrac{a_2}{a_1}=\dfrac{3/4}{1}=\dfrac{1}{4}$
Now, $ S_{n}=\dfrac{a_1}{(1-r)}=\dfrac{3}{1-\dfrac{3}{4}}$
Our answer is: $ S_{n}=\dfrac{3}{3/4}=4$
