Given:
To write the sigma notation for the given infinite series, we first note the Infinite Geometric Series formula:
where:
r=common ratio
a=first term
We can get the common ratio by:
27(1/3)=9
9(1/3)=3
1(1/3)=1/3
Now, we can conclude that the common ratio is 1/3.
Therefore, the sigma notation for the given infinite series is: