Answer
The sum doesn't exist.
Work Step by Step
An infinite geometric series has a sum if and only if $|r|\lt1$, where $r$ is the common ratio. If it exists, then it equals $\frac{a_1}{1-r}$ where $a_1$ is the first term.
Here $r=1.3,a_1=4$
$|1.3|\gt1$, hence the sum doesn't exist.
