find the indicated sum

4 on top of sigma symbol
i=1 on the bottom of sigma symbol
3^i on the right side

please help me figure this out

1 3

2 9
3 27
4 81
------
120

can you break this down, I am having a hard time understanding this concept?

To find the indicated sum, we need to evaluate the expression using sigma notation.

In this case, the sigma symbol (∑) indicates a summation, and the variable i represents the index of the summation. The expression to the right of the sigma symbol, 3^i, represents the terms to be summed.

The notation indicates that we need to start with i=1 and continue until i=4. Let's evaluate the expression step by step:

When i=1, we have 3^1 = 3.
When i=2, we have 3^2 = 9.
When i=3, we have 3^3 = 27.
When i=4, we have 3^4 = 81.

To find the sum of these terms, we add them together:

3 + 9 + 27 + 81 = 120.

Therefore, the indicated sum is 120.