# How do you find the 4-th partial sum of the infinite series #sum_(n=1)^oo(3/2)^n# ?

##### 2 Answers

#### Explanation:

When dealing with a sum, you have a sequence that generates the terms. In this case, you have the sequence

Which means that

Moreover, the

So, in your case, you're looking for

You may compute each term, but there is a useful formula:

So, in your case

Except you are not including

#### Explanation:

This is geometric progression series of which

first term is

Sum